Fait mathématique: 7692 is a value of n for which n and 2n together use each digit 1-9 exactly once.
Culture générale: 7692 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: January 21st is the day in 1954 that the first nuclear-powered submarine, the USS Nautilus, is launched in Groton, Connecticut by Mamie Eisenhower, the First Lady of the United States.