What is the highest common factor of 735 and 630?

The highest common factor (HCF) of two numbers is the largest positive integer that divides both numbers without leaving a remainder. To find the HCF of 735 and 630, we first list the factors of each number: 735 (1, 3, 5, 7, 15, 21, 35, 49, 105, 147, 245, 735) and 630 (1, 2, 3, 5, 6, 7, 9, 10, 14, 15, 18, 21, 30, 35, 42, 45, 63, 70, 90, 105, 126, 210, 315, 630). The highest common factor of 735 and 630 is 105.