What is the greatest common factor of 16?

There is not a greatest common factor of 16 because there cannot be a greatest common factor without two or more numbers to compare. Common factors are factors that the numbers being compared have in common.

The factors of 16 are 1, 2, 4, 8, and 16.

The prime factors of 16 are 2, 2, 2, and 2.
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4