Prime numbers

Is the number 8 prime? ... No, it can be divided by 2

And the number 121? ... by 3 No .. by 7 no ... 11 yes, it can be divided by 11

And 829 .. Ufff, I don't know

With this application you will see a list of the first 5000 primes, and if you don´t find it you can enter the number and you will see either it is prime or the factors