math_fact: 21886 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 21886 is a boring number.
historical_date: December 2nd is the day in 1917 that an armistice is signed between Russia and the Central Powers at Brest-Litovsk and peace talks leading to the Treaty of Brest-Litovsk began.