Mathematical fact: 8779 is is the largest prime factor of 100000000001.
Trivia: 8779 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Historical date: January 13th is the day in 1435 that Sicut Dudum, forbidding the enslavement of black natives in Canary Islands by Spanish natives, is promulgated by Pope Eugene IV.