The GCF is 2.
16 and 24 have a GCF of 8.
8 and 16, among others.
16 and 32 among many others.
Greatest common factor of 16 and 16 is 16.
The greatest common factor of 96 , 16 = 16
Neither 16 nor 36 have a greatest common factor. There is neither a greatest common factor nor common factors of a single number, such as 16, because there cannot be any form of common factor without two or more numbers to compare. Common factors are factors that the numbers being compared have in common. The greatest common factor is the largest factor that all the numbers being compared have in common. Thus, since there are not two or more numbers to compare, there are neither common factors nor a greatest common factor. However, there is a greatest common factor of the pair of 16 and 36. It is 4. See the related question for an explanation on finding the greatest common factor of 16 and 36.
8 and 16, among others.
The greatest factor of 21 and 16 is 21, which is a factor of 21 but not of 16.
The greatest common factor for 16 and 38 is 2.
The greatest common factor of 16 and 34 is 2.
The greatest common factor for 15 and 16 is 1.