We have a little tool that can help with that: Prime Factorization Tool, it also helps to read Prime and Composite Numbers
This tool will work out which Prime Numbers are the factors of the number you enter, but your question said "factors", and not "Prime factors", so there may be combinations that work.
Let's have a go:
7 is a Prime Number, so has no other factors (other than one or itself!) ... Answer: 2 (ie 1 and 7)
9's factors are 3 and 3 ... Answer: 3 (ie 1,3,9)
11 is Prime ... Answer: 2
25's factors are 5 and 5 ... Answer: 3
29 is Prime ... Answer: 2
47 is Prime ... Answer: 2
81 is 3x3x3x3, so it is also 3x27, 9x9 ... Answer: 5 (ie: 1,3,9,27,81)
(I notice that your question said "does the number have just one factor yes or no", so they may have taught that 1 is not a factor, in which case just subtract one from my answers!)