What is 128 expressed as a product of its prime factors?

128/2 = 64

64/2 = 32

32/2 = 16

16/2 = 8

8/2 = 4

4/2 = 2

2/2 = 1

so 128 = 2 x 2 x 2 x 2 x 2 x 2 x 2 = 27