Fait général: 9799 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 9799 is a number with the property that the root-mean-square of its divisors is an integer.
Culture générale: 9799 is an unremarkable number.
Date historique: October 29th is the day in 2008 that Delta Air Lines merges with Northwest Airlines, creating the world's largest airline and reducing the number of US legacy carriers to 5.