input: Write a python function to find the prime factorization of a given number.
  assert prime_factorization(28) == [2, 2, 7]
  assert prime_factorization(15) == [3, 5]
  assert prime_factorization(100) == [2, 2, 5, 5]
output: def prime_factorization(n):
      factors = []
      divisor = 2
      while n >= 2:
          while n % divisor == 0:
              factors.append(divisor)
              n //= divisor
          divisor += 1
      return factors