Fait mathématique: 4013 is a prime factor of 1111111111111111111111111111111111.
Culture générale: 4013 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: December 26th is the day in 1883 that the Harbour Grace Affray between Irish Catholics and Protestant Orangemen causes five deaths in Newfoundland.