How do you write a number as the product of prime numbers using exponents?

Exponents just count how many times each factor is used.

900

450,2

225,2,2

75,3,2,2

25,3,3,2,2

5,5,3,3,2,2

2 x 2 x 3 x 3 x 5 x 5 = 900

2^2 x 3^2 x 5^2 = 900