the greatest common divisor, also known as the greatest common factor or the greatest common factor, refers to the largest divisor shared by two or more integers. the greatest common divisor of a, b is marked as (a, b). similarly, the greatest common divisor of a, b, c is marked as (a, b, c). the greatest common divisor of multiple integers also has the same notation. there are many methods to find the greatest common divisor. common ones include prime factorization method, short division method, euclidean division method, and phase replacement and subtraction method. the concept corresponding to the greatest common divisor is the least common multiple. the least common multiple of a, b is recorded as [a, b].