GCD and LCM calculator finds the greatest common divisor (GCD), also known as Greatest Common Factor (GCF) or Highest Common Factor (HCF), and Least Common Multiple (LCM), also called the Lowest Common Multiple, of two, three and four numbers. Enter two, three or four integers and tap "Calculate". The GCD and LCM calculator finds the prime factorization of numbers (prime factors) and shows the prime factorization in the standard and exponential forms. History list. Sends results via email.