Fatto generale: 5231 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 5231 is an uninteresting number.
Trivia: 5231 is an unremarkable number.
Data storica: April 27th is the day in 1992 that Betty Boothroyd becomes the first woman to be elected Speaker of the British House of Commons in its 700-year history.