40

The number forty is the only number that, in the English language, has all of its letters in alphabetical order.

I am a freak about putting things alphabetically. My books, movies, shoes (by brand), clothes (by brand), and pretty much everything else I own has been placed alphabetically. Because most people do not think like that, I am able to tell when someone has touched or "messed with" something of mine because it won't be placed back in its alphabetical spot. Ironically, 40 is my favorite number and also my lucky number - and subconsciously I think I chose 40 because it is the only number that all of its letters are in alphabetical order.