general_fact: 21997 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 21997 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 21997 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: March 22nd is the day in 1920 that Azeri and Turkish army soldiers with participation of Kurdish gangs attacked the Armenian inhabitants of Shushi (Nagorno Karabakh).