Hi can anyone help me with this?

20^2 x 8^4 x 125 (x meaning multiply)

I have to write in the simplest index notation.
Is there a trick to rewriting the bases in terms of their prime factors?
Or is it all trial and error until you come up with the right combination of numbers???? PLEASE HELP

20^2 = 5^2*2^4

8^4 = 2^12
125 = 5^3

so 20^2 * 8^4 * 125
= (5^5)(2^16)