Fait mathématique: 1131 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Culture générale: 1131 is an uninteresting number.
Date historique: February 4th is the day in 1996 that Major snowstorm paralyzes Midwestern United States, Milwaukee, Wisconsin ties all-time record low temperature at -26°F (-32.2°C).