What is the least common factor of 21 and 63?

To answer the question, "What is the least common factor of 21 and 63?", we will start by defining and listing factors of 21 and 63.

Factors of 21 are all the integers that when multiplied by another integer equal 21. Likewise, factors of 63 are all the integers that when multiplied by another integer equal 63.

The factors of 21 are 1, 3, 7, and 21.

The factors 63 are 1, 3, 7, 9, 21, and 63.

When you ask, "What is the least common factor of 21 and 63?", least is the key word here. Least means smallest. Thus, the smallest or least common factor that 21 and 63 have in common is 1.

Note that all integers, such as 21 and 63, have 1 as one of its factors. Thus, the answer to the least common factor of any two integers greater than 0 will always be 1.

Now that you know the least common factor of 21 and 63, you may also be interested in knowing the greatest common factor of 21 and 63. The greatest factor 21 and 63 have in common, per the list above, is 21.

When you asked for the least common factor of 21 and 63, did you mean least common multiple? If so, the least common multiple of 21 and 63 is 63.

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