General fact: 9900 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 9900 is a boring number.
Trivia: 9900 is an unremarkable number.
Historical date: February 7th is the day in 1819 that Sir Thomas Stamford Raffles leaves Singapore after just taking it over, leaving it in the hands of William Farquhar.