How to Tell if a Number is a Prime Number

This tutorial explains how to determine whether or not a number is a prime number.
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[@learnmathtutorials]

As numbers get larger, it becomes more time consuming to determine if they are prime. If you are wanting to determine if a really large number is prime, it is often better to write a computer program. I recently posted a playlist showing how this is done by writing a C++ computer program. You can find it on either of my KZbin channels if you are interested.

[@TheTheone12360]

im not sure about the dislikes, but you explain it perfectly thank you sir

[@coreychancelor211]

Thank you, after like eight videos I finally find the right one thank you SO much

[@zentertainmenthd1680]

He stopped making videos 6 years ago

[@astouseye4030]

@@zentertainmenthd1680 lol

[@SnehaPatel21]

it was of worth for me because i was before getting confused about the condition for my programming here you have given easy way to understand it helped me :)

[@Syedkobir1]

Helped me so much on my SAT

[@theresamarie3353]

Thanks for posting these algebra videos. Your videos are very helpful, you speak clearly and slow enough for me to follow. I appreciate it. Again thanks for taking the time to do these.

[@heyurmad420hahaha_lalala]

Your comment is 8 years old wohh

[@isabelleparis1581]

Could you please make a video on geometry/ angles? If so that would be great. Thanks!

[@PO1S0N-1]

+Layla Prentice sex represents whether a person is a female or male

[@Ryomojiedits]

Thanks this helped me alot

[@Amo-Jojo.]

Thank you so much after this I understand prime numbers you're the best

[@sampatel7417]

Thanks for the help and other stuff for the help.

[@bigginger519]

my math teacher is making me watch this on my phone

[@childishbambino2024]

Aleem Khan dude it was 3 years ago

[@R4ZRHunterOwner]

I need help so bad I have a p a t today and I still don't get what a prime number up is

[@user-vf1pt2rv8j]

was wondering what vsauce meant when he was "counting prime numbers" and ended up here

[@BANTAlGALLI]

Thank you sir 😊

[@abcd-qn2tn]

How to tell about large values that are they prime or not? For example : Which one of the following is a prime number ? A.161B.221C.373D.437

[@doriz7822]

Thank's for the help

[@nelsonalcantara5731]

you ,re videos are good

[@gosiajelen239]

I have a maths test tommorow. Prime numbers could be in it. This video didn’t explain how to tell if a number is Prime or not😞

[@anthonyfate7759]

same here only diffrence its today for me

[@dariostarsky8124]

With all due respect to you trying to explain primes, I agree with some other comments saying you should change the title ... unless it's a clickbait ... wink, wink If you, however, one day decide to make a video that is more appropriate to the title, you should start by saying that an even number cannot be a prime number (apart from 2, obviously). This will immediately give some insight on the subject to people who are new to primes. Nevertheless, do keep sharing your knowledge, as, clearly, you know stuff ;) All the best, mate.

[@user-vb9nw6zh4m]

Thank you

[@newthought4703]

Thank you.

[@btcls]

This video is good !!!

[@tengkuirdiina]

Thanks!

[@78g476]

this doesn't help with large 3 digit or 4 digit numbers

[@ehznowick489]

+atreya87 tru

[@ehznowick489]

+atreya87 try the largest 2^57885161 - 1 check Adam Spencer's Video

[@magedmorgan1602]

thank you

[@jacksanjeev123]

Thanks paul

[@spanishgamer6368]

Thank u so much

[@St_Elmos_Fire]

I need to know this for a quest on fallout 3 lol

[@last7158]

I can smell that sharpy

[@xMSPSamziixmspgaming]

seriously ... omg so can I

[@matthewmorgan7796]

josh last

[@noelgwekohjr]

Matt

[@gwenythvieira2540]

I can to LOL

[@wasdask1277]

Yyaa

[@ronnelmacompas1647]

thanks man

[@krishnapun2174]

sir I need how to find prime no. or not by some specific formula not by testing factor like u did. if u can do this then I will be helped.

[@karthikrangaraju9421]

I would just say "Autobots roll out"

[@CalligraphyZone234]

Can you make a video on integers

[@jaredarbuckle4060]

Thanks bro

[@abstractpainters964]

What’s easier to learn first-times or divide? Thank you.

[@KBQuick81]

Times

[@zaythings7304]

thanks

[@trentycoipel5996]

can you make a lesson on sets

[@dezelable]

thank you sooo much i have my maths gcse soon so this is so helpful!

[@VickyJ31520]

thanks!---

[@anonymousrecords313]

but wait this doesnt make sense cause if u divide 4 by 4 = 1 so does that mean its a prime??

[@poorandunraj4087]

So divide it by itself and it has to equal 1 and divide it by 1 and it equals itself i get it now thanks that really helped.

[@mohithrgowda8682]

2nd condition for prime numbers can be modified as "THE NUMBERS(positive integer greater than one) SHOULD BE DIVISIBLE ONLY BY 1 AND ITSELF "

[@messitup]

i thought it was a video about : Look at the number 1729, is it a prime??> tell me in 3 seconds kinda of deal, but thanks for the info anyway:)

[@NS-rx1pl]

lol!: I thought it was about: look at the number 1297, is it a prime or not???

[@wasdask1277]

No its not

[@leonardogucci478]

Correct Waste of time shitty contents. Walter.

[@aidenbogoniewski4892]

what is a composite number

[@nestorrodriguez9443]

Awesome lesson thank you.

[@IamChandEvil]

Prime number: an odd positive integer that has no factors other than 1 and itself. An exception is 2, the only even prime number

[@Rihannamca]

I’m trying to study for my aqe but your making it harder

[@hastin.1385]

Anonymous Jesus loves you❤️ U should go to him😊

[@melissaoribel7518]

Now i understand yay!! Thank you!!

[@jourdinsellers4671]

Why use a counter example that "wouldnt be dividing a number by itself"

[@Imparthibank]

It's very useful for me.. thanks!

[@dezelable]

thank you! how do you work out if a large number like 183 is prime?

[@heyurmad420hahaha_lalala]

Wow your comment is 9 years old but are u still there just curious

[@shubr2003]

@@heyurmad420hahaha_lalala wow your comment is 2 years old are you still here just curious.

[@heyurmad420hahaha_lalala]

@@shubr2003 heyyy lol😂 I'm here haha

[@yoshibros1111]

what is pi?

[@RabinNepaliTV]

ice teaching

[@ebenhaezertjondrohartantos4675]

hello, thanks for the explanation, but how to check if this number was a prime number the number = 1737 for example

[@sharpshooter3175]

I know it's a late reply and prolly not the best reply but I was wondering the same thing. I came up with check 1,2,3. So is 1737 divisible by 1 yes obviously. By 2 no. You need it's to end in 1736 or 1738. Meaning you need at minimum the number to end in 0,2,4,6,8. By 3 hard to do but easy. For me I know 1500÷3 is 500 so is 237 divisible by 3. Still hard to do but 210÷3=70. Now you have 27 left over is it divisible by 3. Yes it is 27÷3=9. So 1737÷3=579. Very long winded and prolly works different in your mind but. Try to make it easy and get to the smallest number possible when try to figure if its prime. That's what helped me for larger numbers. So tell me is 2943 prime? No cheating! 😊

[@sharpshooter3175]

Also you can break the number down however you want. For me 1737. I knew 3 times 100 is 300. So I know it's at least 100. How many times does 3 go into 1737. 5 times and some change. So 300×5=1500. That's how I did my math to simplify the problem. So even 2943 I know 3 times 100 is 300. How many times does 300 go its 2943. 9 times. So 300×9=2700. I have 243 left over. 123 method again. 1 works 2 doesnt let's try 3. I know 3×8= 24easy one right. so now 3×80=240 left with 3÷3=1. 2943÷3=981. This means it's not prime because it can be divided by another number besides 1 and itself. Ik it's a lot to read but I hope it helps you understand better.

[@sharpshooter3175]

One last thing the reason I used 123 is because 2 and 4 are pretty much the same if it's not divisible by 4 then 2 should work. Same for 6 and 3. 8 and 4. 7 is unique 9 can be used in place of 6 or 3 again. 5 or 0 is just 5. 25 or 30 is divisible by 5. So I check one 123 first might be easier to use 9 instead but it's my first time ever try to simplify this. 😅 ie 1737÷9 in my brain. 9×100=900. 837 is still a large number to make smaller. So 1 is the first number. 837 made smaller for me let me try 4 since I know 800÷4= 200 then I'm left with 37. And still I'm lost with the larger numbers. 😂 honestly because I have 1 and 200 now then 37 cant be divided by anything so I get 37÷6 is like 6.111so I idk what 1737÷9 is because its doesnt work right in my head lol. So i use 123 to keep it simply. Lol

[@basicallyturtles5069]

You helped my for my exams ty

[@saoirseeehogan9947]

explain rounding

[@5mwa]

learnmathtutorials How do you determine whether an extremely large number is prime. For example a number with 100 digits. I think there is a quicker way than trying to divide it with other primes. Could you tell me how? Thanks =)

[@Subhajit_Paul123]

sorry mate there is no shortcut to determine wheather a number is prime or not.

[@hayhayhay5122]

I got an ad about searching math on KZbin 😂

[@epthestampede4140]

I have to clear this for naplan

[@enderpapikei1274]

I say you made a good example because I struggle with prime numbers along with long division!

[@addisonputman1967]

I agree

[@jayaniewickremasingha3322]

i love it thank you!

[@jikkokikko505]

than you could say this 6dividedby6=1 6dividedby1=6 so that means it could be prime but its not so that was no help

[@demitvedits6255]

Tysmmm

[@akadiamaloney2288]

six can be divided by it self

[@sergiofernandez1863]

six can also be divided by 2 or 3.

[@mudrunner6653]

how can i fined whether 173 is a prime number

[@Subhajit_Paul123]

173 is a prime number

[@mohamedamineelhajjami1034]

i love you duuude

[@kathifields1025]

I looked at wikepedia for a chart of prime numbers and found that 51 was not listed. Is there a reason? Or am I doing something wrong?

[@toma4474]

51=17*3

[@hopeofthewicked]

did any one mention that 2 is the only even prime number?????

[@ItsJustMeAlexis]

noooo???????

[@hopeofthewicked]

absolutely yes

[@Ace-vq3yp]

sam schrenker yeah

[@anuoluwapoayeni132]

That really helped thank you now I get it

[@learnmathtutorials]

Thanks for the question. 51 / 3 = 17. This violates the second condition, therefore 51 is not prime.

[@agotvingno673]

Sorry im not so genius But What is a apositive iteger And BTW Why Your "E" Is Like 3?

[@woshifatpig3633]

Use Google search prime number

[@origamitherapist_55550]

Have u watched Titanic

[@keishagohel5006]

Do one on time

[@user-wp6ml7xr8y]

Sir y one is not prime number ????

[@adamisaacs3930]

4÷4=1

[@kurodoggi3315]

i dont get it :(

[@learnmathtutorials]

For large prime numbers, you want to try dividing them by smaller prime numbers, since all numbers are made up of primes. Therefore when testing, simply test by dividing by, 2,3,5,7,11... and skip the rest. This should save some time. Also here is a useful tip for the number 183. If you add up a numbers digits and that number is divisible by three, then the original number is also divisible by 3, so for 183, 1+8+3 =12 which is divisible by 3, therefore 183 is divisible by 3 and is not prime. : )

[@Starfire777]

I still want to know the definition,HOW is 2,3,5,7 a prime number???

[@samuelspencer5047]

prime numbers are number that can be divided by 1 and itself. e.g 29 29 ÷ 1 = 29 29 ÷ 29 = 1 27, 9 and many more numbers are not just divisible by 1 and itself, but can be divided by 3 and other numbers like 2, 4 etcetera; thus making them not fit to be a prime numbers examples of non prime numbers 27 because it is divisible by more than 2 figures; like: 1, 3 & 27

[@mrcl92rs]

+Samuel Spencer thanks your example turned my light bulb on lol

[@samuelspencer5047]

+carl lee your welcome, also I'm glad that my example is had some value to you :-)

[@sergiofernandez1863]

you cant dived those number by any other number beside 1 and itself without getting a remainder.

[@Starfire777]

Sergio Fernandez GOOD POINT! Thanks

[@Phanterhunter43]

Lets just say prime numbers are odd numbers since they r very similar.

[@EtemBavarian]

Thank you :)

[@thepeggsters3070]

I dont even know what a god damn integer is

[@benperez9626]

Guys Did He Mention The Number 7? no right?

[@jamesmoore8994]

The equations that define the Prime Number Sequence were found and proven 11 years ago: kzbin.info/www/bejne/eHW4p2OBr8-IpJY

[@unicornvloggers50]

I was smart in high school when it came to math. Sat almost 8 years in the house now I'm in college. Math 0950 isn't a hard class but for me I'm struggling already. Wish I did college asap

[@pavanbobade1114]

simple And sweet

[@dr.josegomez7554]

thank you. late HW with my 4th grader.

[@MrMobe127]

Venn diagrams

[@strawbeyysabrina1141]

I don't understand

[@laylowpremix]

I still don't get it !!!!!!!!!!!!!!!

[@aliasv5739]

thx i didnt no what a prime number was im achild

[@donjuandemarco2995]

This is just basic prime

[@aidenbogoniewski4892]

it was so good!!!!!!!!!!!!!!!!!!!!!!!!

[@jasmeetbanwait5727]

Prime numbers are numbers which are only divisible by 1 and themselves. example-19 is a prime number because it can only be divided by 1 and 19.

[@richardrobinson6299]

Good job I know what is a prime number now

[@jasmeetbanwait5727]

Explanation is so difficult...As if it is Rocket Science.

[@malikbourne-benjamin8657]

Yo i got a yt channel its called malik bourne benjamin

[@YoshiRamen]

the sharpy is giving me the shakes when he writes somthing

[@armaanmann1973]

Paul thanks I was totally counfused