Fatto generale: 7881 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 7881 is an unremarkable number.
Trivia: 7881 is an uninteresting number.
Data storica: July 29th is the day in 1793 that John Graves Simcoe decides to build a fort and settlement at Toronto, having sailed into the bay there.