General fact: 81608 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 81608 is an unremarkable number.
Trivia: 81608 is an unremarkable number.
Historical date: June 8th is the day in 1783 that the volcano Laki, in Iceland, begins an eight-month eruption which kills over 9,000 people and starts a seven-year famine.