Fait général: 1650 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 1650 is the number of connected partial orders on 7 unlabeled elements.
Culture générale: 1650 is an unremarkable number.
Date historique: July 7th is the day in 1981 that U.S. President Ronald Reagan appoints Sandra Day O'Connor to become the first female member of the Supreme Court of the United States.