Hecho general: 1650 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 1650 is the number of connected partial orders on 7 unlabeled elements.
Trivia: 1650 is an uninteresting number.
Fecha histórica: July 7th is the day in 1946 that Howard Hughes nearly dies when his XF-11 spy plane prototype crashes in a Beverly Hills neighborhood.