general_fact: 6339 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 6339 is an unremarkable number.
trivia: 6339 is a boring number.
historical_date: May 9th is the day in 1671 that Thomas Blood, disguised as a clergyman, attempts to steal England's Crown Jewels from the Tower of London.