The number of factors of a number can be determined using the following method.
Let's use 45 as an example.
First, we want to prime factorize the number. In this case, we get 3^2 * 5^1.
Next, you want to take each of the exponents and increase them by 1. This gives us 3^3 * 5^2.
Now we multiply all of the exponents. 3*2=6.
As we can see, 45 has 6 factors. 1, 3, 5, 9, 15, 45.
This is useful for calculating the number of factors of larger numbers.