Question: 12 is a prime factor?
Answer: For example, 5 is a prime number, because the only factors of 5 are 1 * 5 = 5. However, 12 is not a prime number, because 1 * 12 = 12, 2 * 6 = 12, and 3 * 4 = 12. Prime factorization means finding all the prime numbers that are factors of a number. 2 If the last digit is even, the number is divisible by 2.