besides 45 and 1, what is one factor of 45?

Explanation:

Step1: List factor - finding method

Find pairs of numbers that multiply to 45.

Step2: List factor pairs

$1\times45 = 45$, $3\times15 = 45$, $5\times9 = 45$.

Answer:

3 (or 5 or 9 or 15)