Given two whole numbers m and n , if there exists another whole number k such that n = mk, then we say that m divides n or n is divisible by m.

Example

1. 10=2×5 and this implies both 2 and 5 divide 10. That is, 10 is divisible by both 2 and 5.
2. 30 is not divisible by 4, because there is no whole number that can be multiplied by 4 to give us 30. For example, 4×7 = 28 , 4×9 = 36 and 28<30<36.

Determine the divisibility of a given by another number worth considering it. For any natural number n , n = n×1 = n and this implies every whole number is divisible by 1.