The letter 'C' in "GCF" stands for the word "common". "Common" means "same for both".
There's nothing common about one single thing, and no single number has a 'common' factor
or a GCF. Common factors and GCFs can only come from two or more numbers.
1 is the GCF of 33 and 31 because 31 is a prime number.
The GCF is 33.
66
The GCF of 33 and 66 = 33
1 It is a relatively prime number.
The GCF is 33.
The GCF is 33.
The GCF is 1.
The GCF is 3.
The GCF is 11.
The GCF of 33 and 96 is 3.
The GCF is 3.