Fatto generale: 28383 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 28383 is an unremarkable number.
Trivia: 28383 is a boring number.
Data storica: September 15th is the day in 1968 that the Soviet Zond 5 spaceship is launched, becoming the first spacecraft to fly around the Moon and re-enter the Earth's atmosphere.