Fatto generale: 4727 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 4727 is the sum of the squares.
Trivia: 4727 is an unremarkable number.
Data storica: December 9th is the day in 1950 that Harry Gold is sentenced to 30 years in jail for helping Klaus Fuchs pass information about the Manhattan Project to the Soviet Union.