general_fact: 20565 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 20565 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 20565 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: April 20th is the day in 1916 that the Chicago Cubs play their first game at Weeghman Park (currently Wrigley Field), defeating the Cincinnati Reds 7-6 in 11 innings.