Write a function that returns true if the given number num is a product of any two prime numbers.
product_of_primes(2059) ➞ true
# 29*71=2059
product_of_primes(10) ➞ true
# 2*5=10
product_of_primes(25) ➞ true
# 5*5=25
product_of_primes(999) ➞ false
# There are no prime numbers.num is always greater than 0.0 and 1 aren't prime numbers.