[Haskell-cafe] Int->[Char] conversion

Hi, I am working through Hal Daume's tutorial, trying to do the exercises. I can't figure out how to output an integer with putStrLn (or any other way), I think I need an Int -> [Char] conversion but couldn't find it. Specifically, in Exercise 3.10, I have the product of numbers in pp, and would like to do putStrLn ("Product: " ++ convertnumbertostring(pp)) but I don't know which function does this... Sorry for the extremely dumb question. Thanks, Tamas