Hecho general: 7231 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 7231 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Trivia: 7231 is a boring number.
Fecha histórica: October 18th is the day in 1356 that Basel earthquake, the most significant historic seismological event north of the Alps, destroys the town of Basel, Switzerland.