general_fact: 16729 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 16729 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 16729 is an uninteresting number.
historical_date: October 19th is the day in 1866 that Venice - Annexion of Veneto and Mantua to Italy - At Hotel Europa, Austria hands over Veneto to France, which hands it immediately over to Italy.