Common factors of 9 and 7?

The common factors of 9 and 7 are the numbers that can evenly divide both 9 and 7 without leaving a remainder. In this case, the only common factor of 9 and 7 is 1, as 9 is a Prime number and only has 1 and itself as factors. Therefore, the common factors of 9 and 7 are 1.