Fatto generale: 9997 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 9997 is an unremarkable number.
Trivia: 9997 is an uninteresting number.
Data storica: May 15th is the day in 1972 that the island of Okinawa, under U.S. military governance since its conquest in 1945, reverts to Japanese control.