Mathematical fact: 51637 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 51637 is a boring number.
Historical date: May 17th is the day in 1987 that an Iraqi Dassault Mirage F1 fighter jet fires two missiles into the U.S. Navy warship USS Stark, killing 37 and injuring 21 of her crew.