Fatto generale: 54551 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 54551 is an uninteresting number.
Trivia: 54551 is an unremarkable number.
Data storica: May 9th is the day in 1961 that Jim Gentile of the Baltimore Orioles becomes the first player in baseball history to hit grand slams in consecutive innings.