Question

Find the number of divisors of $180$

Answer 1

$180=2\times 2\times 3\times 3\times 5$

$=2^2\times 3^2\times 5^1$

Number of divisors$=(2+1)(2+1)(1+1)=3\times 3\times 2=18$

Number of odd divisors$=(2+1)(1+1)=3\times 2=6$

Number of even divisors of $180=18-6=12$