How many factors of 1,080 are perfect squares?

Explanation

1. 01

   $1{,}080 = 2^3 \times 3^3 \times 5$.

2. 02

   A square factor uses even powers only: 2 to the power 0 or 2, 3 to the power 0 or 2, and 5 to the power 0.

3. 03

   Square factors = $2 \times 2 \times 1 = 4$ (they are 1, 4, 9, 36).