Mathematical fact: 4279 is the smallest semiprime super Catalan number.
Trivia: 4279 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Historical date: September 18th is the day in 2007 that Pervez Musharraf announces that he will step down as army chief and restore civilian rule to Pakistan, but only after he is re-elected president.