144, 324, 576, 900
102
16
9
64
16
144
There can't be a prime number that has a square root because the square root would be a factor of the number.
16.
16
36
The number of digits in the square root of a number depends on the number. If it is a square number, the square root will have a finite number of digits. If the number is not a square number then the square root will be an irrational number with an infinite, non-repeating decimal representation. In both cases, the number of digits before the decimal point, in the square root of x will be the rounded value of 1+0.5*log10(x)
It is the square of any one of the four multiples of 6 between 10 and 31.