Fatto generale: 1633 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 1633 is a number whose square and cube use different digits.
Trivia: 1633 is an unremarkable number.
Data storica: June 20th is the day in 1979 that ABC News correspondent Bill Stewart is shot dead by a Nicaraguan soldier under the regime of Anastasio Somoza Debayle.