Fatto generale: 91884 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 91884 is an unremarkable number.
Trivia: 91884 is an uninteresting number.
Data storica: July 27th is the day in 1054 that Siward, Earl of Northumbria invades Scotland and defeats Macbeth, King of Scotland somewhere north of the Firth of Forth.