This cannot be answered because the common multiples of any two or more numbers are infinite.
A common multiple of 9 and 21 is 63
The Greatest Common Factor of 9, 18, 21: 3
The least common multiple of 7 , 9 , 21 = 63
The Greatest Common Factor of 60, 21, 9: 3
The greatest common multiple of any set of integers is infinite.
The Greatest Common Factor of 21, 9 is 3.
The greatest common multiple of any set of integers is infinite.
There is no greatest common multiple as whatever number is claimed to be the greatest, the lowest common multiple of them (216) can be added to get an even greater common multiple.
A common multiple of 9 and 21 is a number of the form 63*k where k is an integer.
The greatest common multiple is an infinite amount and not very practical for problem solving.
The Least Common Multiple (LCM) for 9 21 10 12 is 1,260.
least common multiple of 3 9 and 21 is 63.