Fatto generale: 6407 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 6407 is an uninteresting number.
Trivia: 6407 is an uninteresting number.
Data storica: July 16th is the day in 1910 that John Robertson Duigan makes the first flight of the Duigan pusher biplane, the first aircraft built in Australia.