Divisibility Rules
Divisible by 2: Last digit is even (0, 2, 4, 6, 8)
Divisible by 3: Sum of digits is divisible by 3
Divisible by 4: Last two digits form a number divisible by 4
Divisible by 5: Last digit is 0 or 5
Divisible by 6: Divisible by both 2 and 3
Divisible by 7: Double the last digit, subtract from remaining number; repeat if needed
Divisible by 8: Last three digits form a number divisible by 8
Divisible by 9: Sum of digits is divisible by 9
Divisible by 10: Last digit is 0
Divisible by 11: Alternating sum of digits is divisible by 11
Divisible by 12: Divisible by both 3 and 4
Divisible by 13: Multiply last digit by 9, subtract from remaining number; repeat if needed
Divisible by 14: Divisible by both 2 and 7
Divisible by 15: Divisible by both 3 and 5