def is_powerful(n): """if a prime p divides n then p^2 must also divide n (also called squareful, square full, square-full or 2-full numbers). """ for f in itertools2.unique(math2.prime_factors(n)): if n%(f*f): return False return True
def is_product_of_2_primes(n): f=list(math2.prime_factors(n)) return len(f)==2 and f[0]!=f[1]