The least perfect square, which is divisible by each of 21, 36 and 66 is:
Answer: A
L.C.M. of \(21, 36, 66 = 2772\)
Now, \(2772 = 2 \times 2 \times 3 \times 3 \times 7 \times 11\)
To make it a perfect square, it must be multiplied by \(7 \times 11\)
So, required number
\(= 22 \times 32 \times 72 \times 112\\
= 213444\)