Hecho general: 63908 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 63908 is an unremarkable number.
Trivia: 63908 is an uninteresting number.
Fecha histórica: December 21st is the day in 1988 that a bomb explodes on board Pan Am flight 103 over Lockerbie, Dumfries and Galloway, Scotland, killing 270.