General fact: 9917 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 9917 is an uninteresting number.
Trivia: 9917 is an uninteresting number.
Historical date: February 24th is the day in 1942 that the Battle of Los Angeles, one of the largest documented UFO sightings in history; the event lasted into the early hours of February 26, 1942.