general_fact: 9421 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 9421 is a value of n for which n and 8n together use each digit 1-9 exactly once.
trivia: 9421 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: October 16th is the day in 1780 that Royalton, Vermont and Tunbridge, Vermont are the last major raids of the American Revolutionary War.