How many numbers from 1 to 125 are perfect powers? (A perfect power is a number of the form a^b, where a > 1 and b > 1.)
2^2, 2^3, 2^4, 2^5, 2^6, 3^2, 3^3, 3^4, 4^2, 4^3, 5^2, 5^3, 6^2, 7^2, 8^2, 9^2, 10^2, 11^2 = 18
