math_fact: 18816 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 18816 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: July 7th is the day in 1898 that U.S. President William McKinley signs the Newlands Resolution annexing Hawaii as a territory of the United States.