# Thread: Find All Primes of a Number

1. ## Find All Primes of a Number

Determine all of the primes that divide the number 100!

2. Originally Posted by fifthrapiers
Determine all of the primes that divide the number 100!
You can write it out as,
100!=100(99)....(2)(1)

Thus, 100! is divisible by p if and only if p divides those factors if and only if p divides one of those factors.
Thus, it is all primes up to 100.