General fact: 84564 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 84564 is a boring number.
Trivia: 84564 is an unremarkable number.
Historical date: July 12th is the day in 1970 that a fire consumes the wooden home of Norwegian composer Geirr Tveitt and irretrievably destroys about 90 percent of his output.