general_fact: 6428 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 6428 is a boring number.
trivia: 6428 is an uninteresting number.
historical_date: August 6th is the day in 1926 that Harry Houdini performs his greatest feat, spending 91 minutes underwater in a sealed tank before escaping.