Fait mathématique: 2272 is the number of graphs on 7 vertices with no isolated vertices.
Culture générale: 2272 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: March 21st is the day in 1965 that Martin Luther King, Jr. leads 3,200 people on the start of the third and finally successful civil rights march from Selma to Montgomery, Alabama.