Remark before use

This app can be used by Firefox 32.0.2, Chrome 37, Safari for iPhone (iOS 7.1.2).
The rule book can be downloaded from here (Japanese).

Please press the "LOAD PRIMES!" button.

You need initialize this application!

Now loading...

Prime or not?

Input a number!
Prime or not? Prime?
Prime factorization

Do you need the usage of this application?


  1. You must press the "LOAD PRIMES!" button to load the prime list.
  2. You get a textbox to input the number.
  3. Input the number and push "ENTER" or the button.
  4. You will get the result!


The number 57 is the celebrated Grothendieck prime in this app because of the rule.

Negative numbers are converted to positive numbers.

I made some prime number list and load it for prime numbers processing .
I also use this list to factorize integers.
Please tell me a more better prime number list if you know!