441 is odd, so we can't divide it by 2.
Since the sum of its digits is , which is divisible by 3, we can divide 441 by 3, and we have
Which is still divisible by 3, because . We have
49 is not divisible by 3 anymore, nor by 5 (it doesn't end with 0 or 5).
It is divisible by 7 though, we have
and finally,
So, the factorization of 441 is