Divisibility rules
A number is divisible by the given integer if the condition is met.

2 - If the last digit is a 0, 2, 4, 6, or 8
3 - If the sum of the digits is divisible by 3
4 - If the last two digits are divisible by 4
5 - If the last digit is a 0 or 5
6 - If the number is divisible by both 2 and 3.
8 - If the last three digits are divisible by 8
9 - If the sum of the digits is divisible by 9
10 - I f the last digit is a 0

Perfect squares are:

1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144

PRIME NUMBERS to 100 are:

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43,  47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97