It is: 31*31 = 961
The largest perfect square factor of 48 is 16.
It is: 36 because 6*6 = 36
There can be only one perfect square for a number and for 205200000 it is 42,107,040,000,000,000
√1476 ≈ 38.419, so the largest perfect square less than 1476 would have to be 382, or 1444.
The largest 5 digit perfect square is 99856 = 3162
9801
64
36
17424
16
25
100