general_fact: 20163 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 20163 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 20163 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: March 15th is the day in 1917 that Tsar Nicholas II of Russia abdicates the Russian throne and his brother the Grand Duke becomes Tsar.