First, prime factorize the number. Take the exponent values, add one, and then find their product

Example: 54=2^1 x 3^3 

(1+1)(3+1)= 2 * 4

Therefore, 54 has 8 factors

Theory: This is kind of finding the number of combinations possible. You add one because you need to include the single values of the prime numbers

in 54, that would mean 1*2 or 1*3.