Q: How many factors of 155^9 are perfect squares and/or perfect cubes?
A: 37 factors of 155^9 are perfect squares and/or perfect cubes.
155 is a composite number composed of 5 x 31.
Therefore
155^9 = 5 x 5 x 5 x 5 x 5 x 5 x 5 x 5 x 5 x 31 x 31 x 31 x 31 x 31 x 31 x 31 x 31 x 31
25 Perfect Squares:
1: 1 is both a perfect square and a perfect cube.
4: Perfect squares with just 5s = 5^2, 5^4, 5^6, 5^8
4: Perfect squares with just 31s = 31^2, 31^4, 31^6, 31^8
Combining the 5s and the 31s Perfect Squares
4: 5^2 x 31^ 2, 5^4 x 31^2, 5^6 x 31^2, 5^8 x 31^2
4: 5^2 x 31^ 4, 5^4 x 31^4, 5^6 x 31^4, 5^8 x 31^4
4: 5^2 x 31^ 6, 5^4 x 31^6, 5^6 x 31^6, 5^8 x 31^6
4: 5^2 x 31^8, 5^4 x 31^8, 5^6 x 31^8, 5^8 x 31^8
12 Perfect Cubes:
Perfect cubes with just 5s = 5^3, 5^6 (already counted above), 5^9 (2)
Perfect cubes with just 31s = 31^3, 31^6 (already counted above), 31^9 (2)
Combining the 5s Perfect Cubes and the 31s Perfect Cubes
5^3 x 31^3, 5^6 x 31^3, 5^9 x 31^3 (3)
5^3 x 31^6, 5^9 x 31^6 (2)
5^3 x 31^9, 5^6 x 31^9, 5^9 x 31^9 (3)