The factors of 225 is 5×5×3×3 and the factors of 441 is 3×3×7×7. Then,
225441=5×5×3×33×3×7×7
Taking square roots both sides,
√225441=√5×5×3×33×3×7×7
=√52×3232×72
=√(5×33×7)2
=5×33×7
=1521
Therefore, the square root of 225441 is 1521.