Answer
$7\times7\times3\times3$
Work Step by Step
Since the sum of the digits of $441$ add up to $9$, it is divisible by $9$. When we divide $441$ by $9$ we get $49$. $49$ is the perfect square of $7$, and can be broken down into prime factors $7\times7$. $9$ can be broken down into prime factors $3\times3$. Since $3$ and $7$ are prime numbers, the prime factorization of $441$ is $7\times7\times3\times3$
