Fatto generale: 733 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 733 is the sum of the digits of 4^{4^{4}}.
Trivia: 733 is an unremarkable number.
Data storica: January 2nd is the day in 1927 that Angered by the anti-clerical provisions of the Mexican Constitution of 1917, Catholic rebels in Mexico rebelled against the government.