A number is divisible by $18$ if it is divisible by both $3$ and $6$.

If a number is divisible by $3$ and $7$, it must be divisible by $21$.

The sum of two consecutive odd numbers is always divisible by $4$.

If a number divides two numbers exactly, it must divide their sum exactly.

Give the prime factorization of the following number.

$12$

Give the prime factorization of the following number.

$18$

Give the prime factorization of the following number.

$48$

Give the prime factorization of the following number.

$56$

Give the prime factorization of the following number.

$90$