general_fact: 9753 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
math_fact: 9753 is a value of n for which 4n and 5n together use each digit exactly once.
trivia: 9753 is an unremarkable number.
historical_date: September 13th is the day in 1964 that South Vietnamese Generals Lam Van Phat and Duong Van Duc fail in a coup attempt against General Nguyen Khanh.