Question

Find number of divisors of 12100, also find number of even divisors.

Answer 1

12100 = 11^2 * 2^2* 5^2
Number of factors = 3*3*3= 27

(We add 1 to exponents and multiply) .
Number of Factors of 12100/2 : will be The number of even factors of 12100. So 3 * 2 * 3 =18.
Answer = 18 even factors.
Another way:
Odd factors of 12100 are that of 11^2 * 5^2. There are hence 3*3= 9 odd factors. Subtract from 27 to get 18.