What is the square root of 441?

$$441 = 3 \times 147$$ $$147 = 3 \times 49$$ $$49 = 7 \times 7$$

So, the prime factorization of 441 is $3 \times 3 \times 7 \times 7 = 3^2 \times 7^2$.

$$\sqrt{3^2 \times 7^2} = \sqrt{3^2} \times \sqrt{7^2}$$ $$= 3 \times 7$$ $$= 21$$

The square root of 441 is:

$$21$$