Hello,

A perfect square is the product of perfect square, that is to say numbers put to an even power.

Here, 2^5 has to be multiplied by 2 to make an even power, and thus a perfect square.

3=3^1 has to be multiplied by 3 to make an even power, and thus a perfect square.

5^2 is already a perfect square

7^3 has to be multiplied by 7 to make an even power, and thus a perfect square.

n=2x3x7