General fact: 7752 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 7752 is the generalized Catalan number C(14,5).
Trivia: 7752 is a boring number.
Historical date: March 22nd is the day in 1916 that the last Emperor of China, Yuan Shikai, abdicates the throne and the Republic of China is restored.