The divisor is a factor. The quotient (b≠0) obtained by dividing the integer A by the integer B is exactly an integer without remainder, so we say that A can be divisible by B or B can be divisible by A ... A is called a multiple of B, and B is called a divisor of A.

According to peishu theorem, for every pair of integers a and b, there is a common factor d, which makes d? =? Ax+by, where x and y are integers, and every common factor of a and b can be divisible by this d, then the absolute value of d is called the greatest common factor.

Within the range of natural numbers (0 and positive integers),

Any positive integer is a divisor of 0.

The positive divisor of 4 is: 1, 2,4.

The positive divisor of 6 is 1, 2, 3, 6.

The positive divisor of 10 is: 1, 2,5, 10.

The positive divisors of 12 are: 1, 2,3,4,6, 12.

The positive divisor of 15 is: 1, 3,5, 15.

The positive divisor of 18 is: 1, 2,3,6,9, 18.

The positive divisors of 20 are: 1, 2, 4, 5, 10, 20.