math_fact: 11623 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 11623 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: October 27th is the day in 1904 that the first underground New York City Subway line opens; the system becomes the biggest in United States, and one of the biggest in world.