I am not a numerologist, does it have some deeper/hidden meaning?
There are a lotta things special about the number 42 (most that I don't care about) but I 'spose you could start with The Hitchhiker's Guide To The Galaxy or the second book, The Restaurant At The End of the Universe. There were 5, or maybe 6, books in the series (it's been a long time ago in a galaxy far, far away that I read that stuff).