Answer
$3^{3}\times5$
Work Step by Step
In order to find the prime factorization of 135, we can try to divide 135 by the first prime, 2.
135 cannot be divided by 2, so we divide by the next prime, 3.
$135\div3=45$
45 cannot be divided by 2, so we divide by 3.
$45\div3=15$
15 cannot be divided by 2, so we divide by 3.
$15\div3=5$
5 itself is a prime number, so we cannot simplify any more. The prime factorization of 135 is $3\times3\times3\times5=3^{3}\times5$.