+0

+3
73
2
+344

How many positive divisors of 30! are prime?

Jul 29, 2020

#1
+1154
+1

We could prime factorize the numbers below 30 and get the list
2,3,5,7,11,13,17,19,23,29

and  that is $$\boxed{10\text{ numbers}}$$

Jul 29, 2020
#2
+8
0

Because a prime number is a number that can not be divisible by any number except for itself and one, you can just list the prime numbers under and/or equal to 30. Every composite, or non-prime, is divisible by at least two prime numbers.

Jul 29, 2020