Fatto generale: 84789 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 84789 is an uninteresting number.
Trivia: 84789 is an unremarkable number.
Data storica: February 22nd is the day in 1957 that Ngo Dinh Diem of South Vietnam survives a communist shooting assassination attempt in Ban Me Thuot.