$\sqrt{2016n}$. Solve for $n$

Question

What is the smallest natural number $n$ possible for $\sqrt{2016n}$ to be a whole integer?

I can solve it by using a calculator and with trial and error but I think I have to solve it without a calculator. How would you go about the question?

Thank you

Answer 1

Guide:

$$2016 = 2^5\cdot 3^2 \cdot 7$$

This is not a square because the power of $2$ and $7$ are odd. What do you have to multiply to make them even?