Fatto matematico: 1717 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 1717 is a boring number.
Data storica: September 12th is the day in 1974 that Emperor Haile Selassie of Ethiopia, 'Messiah' of the Rastafari movement, is deposed following a military coup by the Derg, ending a reign of 58 years.