#### Answer

$5^{2}$

#### Work Step by Step

In order to find the prime factorization of 25, we can try to divide 25 by the first prime, 2.
25 cannot be divided by 2 or 3, so we divide by the next prime, 5.
$25\div5=5$
5 itself is a prime number, so we cannot simplify any more. The prime factorization of 25 is $5\times5=5^{2}$.