Every composite number can be written as a product of prime numbers. This is called prime factorization. The representation is unique (ignoring order).
Example: 12 = 2 × 2 × 3. The prime factors are 2 (appears twice) and 3. Another way to write this: 12 = 2² × 3.
To find prime factorization, divide by the smallest prime repeatedly until you reach 1. For 12: divide by 2 to get 6, divide by 2 again to get 3, then 3 is prime.