Find the greatest common factor of two or three numbers by short division? Multiply all divisors until they are coprime. If the common factor of several numbers is only 1, they are said to be coprime.
If two numbers are multiples, then the smaller number is their greatest common factor. If two numbers are coprime, then 1 is their greatest common factor.
For example, the common divisors of 12 and 16 are 1, 2 and 4, the largest of which is 4, which is the greatest common divisor of 12 and 16, generally denoted as (12,/kloc. The greatest common divisor of 12, 15 and 18 is 3, and it is (12, 15, 18)=3.
Extended data
Only under the condition of divisibility will there be the concepts of factor and multiple. Multiplies and factors are interdependent and cannot exist separately. First, when it comes to factors and multiples, we can only say who is whose multiple or who is whose factor. For example, it is wrong to say that 6 is a multiple and 3 is a factor.
Secondly, the relationship between multiples and factors of two integers is mutual: if A is a multiple of B, then B must be a factor of A; Conversely, if a is a factor of b, then b must be a multiple of a.
The number of factors of a number is limited. The smallest factor of a number is 1, and the largest factor is itself. The factor of 1 is only 1, and the maximum and minimum factors are all 1. Integers other than 1 have at least two factors.
Baidu Encyclopedia-Common Factor
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