gcf of 53 and 63 is 1.
The number 9 would be the GCF, or greatest common factor, of 18 and 63.
The GCF is: 63
The GCF is 21.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 9.
The GCF is 9.
The GCF is 9.
The GCF is 9.
The GCF is 7.