Find the least number which must be subtracted from the following number to make them a perfect square:

$26535$

Find the least number which must be subtracted from the following number to make them a perfect square:

$161605$

Find the least number which must be subtracted from the following number to make them a perfect square:

$4401624$

Find the least number which must be added to the following number to make them a perfect square:

$5607$

Find the least number which must be added to $4931$ to make them a perfect square.

Find the least number which must be added to the following number to make them a perfect square:

$4515600$

Find the least number which must be added to $37460$ to make it a perfect square.

Find the least number which must be added to the following number to make them a perfect square:

$506900$