math_fact: 18902 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 18902 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: October 1st is the day in 1940 that the Pennsylvania Turnpike, often considered the first superhighway in the United States, opens to traffic.