A prime number that exactly divides a given number.

### Examples

- The prime divisors of 15 are: {3, 5}
- The prime divisors of 18 are: {2, 3}
- The prime divisors of 42 are: {2, 3, 7}
- The set of prime divisors of 60 is {2, 3, 5}.

A prime number that exactly divides a given number.

- The prime divisors of 15 are: {3, 5}
- The prime divisors of 18 are: {2, 3}
- The prime divisors of 42 are: {2, 3, 7}
- The set of prime divisors of 60 is {2, 3, 5}.