Fait mathématique: 2196 is the only number n so that 2n, 3n, 7n, and 9n together contain every digit 1-9 exactly twice.
Culture générale: 2196 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: January 4th is the day in 1972 that Rose Heilbron becomes the first female judge to sit at the Old Bailey in London, England, United Kingdom.