What are the single digit factors of 2100?

The single-digit factors of 2100 are 1, 2, 3, 4, 5, 6, 7, 8, and 9. However, among these, the actual factors of 2100 are 1, 2, 3, 4, 5, 6, and 7. The number 8 and 9 are not factors of 2100. Thus, the complete list of single-digit factors is 1, 2, 3, 4, 5, 6, and 7.