General fact: 877 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 877 is the 7^{th} Bell number.
Trivia: 877 is an unremarkable number.
Historical date: May 26th is the day in 1647 that Alse Young, hanged in Hartford, Connecticut, becomes the first person executed as a witch in the British American colonies.