Question 43991
If you can divide 27 by something and get a whole number as asn answer, that something is a factor of 27.
Start with dividing 27 by one, then try dividing 27 by 2, etc. and list the numbers which give good solutions. 
You should find the factors are 1, 3, and 9.

I hope this helps.

P.S. I am trying to start my own mathematics homework help website.  I would be extremely grateful if you would send me your feedback on my help to adam.chapman@student.manchester.ac.uk.