Fait général: 5431 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fait mathématique: 5431 is the smallest number whose 4^{th} power contains 5 consecutive 9's.
Culture générale: 5431 is a boring number.
Date historique: November 13th is the day in 1995 that a truck-bomb explodes outside of a US-operated Saudi Arabian National Guard training center in Riyadh, killing five Americans and two Indians.