Find the greatest number of six digits which is a perfect square.

Explanation

We know the greatest number of `6` digits is `999999`.
Then solving through long division method,
We get a quotient of `999.99`. So it is not a perfect square.
But if we consider it to be as `(1000-1)²` which will be equal to `999²`.
`(1000 - 1)² = 999² = 998001`
.·.The greatest `6`-digit number which is a perfect square is `998001`.