general_fact: 7211 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 7211 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 7211 is a boring number.
historical_date: September 28th is the day in 1951 that CBS makes the first color televisions available for sale to the general public, but the product is discontinued less than a month later.