Fait mathématique: 1109 is the only 4 digit number whose 2-digit substrings are consecutive.
Culture générale: 1109 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: January 13th is the day in 1972 that Prime Minister Kofi Abrefa Busia and President Edward Akufo-Addo of Ghana are ousted in a bloodless military coup by Colonel Ignatius Kutu Acheampong.