General fact: 67731 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 67731 is an uninteresting number.
Trivia: 67731 is a boring number.
Historical date: June 9th is the day in 1928 that Charles Kingsford Smith completes the first trans-Pacific flight in a Fokker Trimotor monoplane, the Southern Cross.