21
Chat with our AI personalities
The greatest or highest common factor is 1
The Greatest Common Factor (GCF) of 13 and 20 is: 1
The greatest common factor of 20, 21, and 25 is 1. Although 20 and 25 can be divisible by 5, 21 can not. Therefore, the only common factor between these three numbers is 1 and it's the greatest one as well.
The GCF of 19 and 20 is 1.
The two numbers are coprime, so their greatest common factor is 1.