# What is the prime factorization of 3 and 7?

3 is a prime number. It is only evenly divisible by itself and
one.

7 is a prime number. It is only evenly divisible by itself and
one.

### Is 21 x 2 the prime factorization of 42?

Prime Factorization of 42 No, 21 X 2 is not the prime factorization of 42 because 21 is a composite number. 2 X 3 X 7 is the prime factorization of 42 because all the factors are prime numbers. To arrive at the prime factorization in this particular case, you had to factor 21 down to its prime factors, not forgetting that one of the prime factors of 42 was already 2. 2 X 21…