general_fact: 6438 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 6438 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
trivia: 6438 is an uninteresting number.
historical_date: August 16th is the day in 1929 that the 1929 Palestine riots break out in the British Mandate of Palestine between Arabs and Jews and continue until the end of the month.