Greatest number both 42 and 56 are divisible by?

The greatest number that both 42 and 56 are divisible by is their greatest common divisor (GCD). To find the GCD, we can list the factors of each number: the factors of 42 are 1, 2, 3, 6, 7, 14, 21, and 42; the factors of 56 are 1, 2, 4, 7, 8, 14, 28, and 56. The largest common factor is 14, so the GCD of 42 and 56 is 14.