Divisibility criteria

• Divisibility of numbers by 2, 4, 8, 3, 9, 6, 5, 25, 10, 100, 1000, 11.

1. Divisibility by 2. A number is divisible by 2, if its last digit is 0 or is divisible by 2. Numbers, which are divisible by 2 are called even numbers. Otherwise, numbers are called odd numbers.
2. Divisibility by 4. A number is divisible by 4, if its two last digits are zeros or they make a two-digit number, which is divisible by 4.
3. Divisibility by 8. A number is divisible by 8, if its three last digits are zeros or they make a three-digit number, which is divisible by 8.
4. Divisibility by 3 and by 9 . A number is divisible by 3, if a sum of its digits is divisible by 3. A number is divisible by 9, if a sum of its digits is divisible by 9.
5. Divisibility by 6. A number is divisible by 6, if it is divisible by 2 and by 3.
6. Divisibility by 5. A number is divisible by 5, if its last digit is 0 or 5.
7. Divisibility by 25. A number is divisible by 25, if its two last digits are zeros or they make a number, which is divisible by 25.
8. Divisibility by 10. A number is divisible by 10, if its last digit is 0.
9. Divisibility by 100. A number is divisible by 100, if its two last digits are zeros.
10. Divisibility by 1000. A number is divisible by 1000, if its three last digits are zeros.
11. Divisibility by 11. A number is divisible by 11 if and only if a sum of its digits, located on even places is equal to a sum of its digits, located on odd places, OR these sums are differed by a number, which is divisible by 11.