Prime factorization

The prime factorization of a whole number is the list of prime numbers that multiply to give it. For example, 60 = 2 × 2 × 3 × 5, usually written 60 = 2² × 3 × 5.

Every whole number greater than 1 has exactly one prime factorization, no matter how you find it. That is why two different factor trees for the same number always end with the same primes. The prime factorization is also what gives the greatest common factor and the least common multiple of two numbers.