math_fact: 21815 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 21815 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
historical_date: September 22nd is the day in 1792 that Primidi Vendémiaire of year 1 of the French Republican Calendar as the French First Republic comes into being.