The greatest common divisor (GCD) of 24 and 1 is 1. To find the GCD, you can list the factors of each number and find the largest common factor among them. The factors of 24 are 1, 2, 3, 4, 6, 8, 12, and 24, while the factors of 1 are 1 and itself. The only common factor between these two numbers is 1, so the GCD of 24 and 1 is 1