It is: 1
The GCF of 40 and 63 is 1 (one).
The greatest common factor of 40 and 63 is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
The GCF is 1.
73 is a prime number. It's only factors are 1 and 73. The only common factor of 73 and 40 is 1.
The GCF is: 63
The GCF is 21.
The GCF is 9.
The GCF is 63.
The GCF is 9.