Hecho general: 8172 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Hecho matemático: 8172 is an unremarkable number.
Trivia: 8172 is an unremarkable number.
Fecha histórica: May 16th is the day in 1527 that the Florentines drive out the Medici for a second time and Florence re-establishes itself as a republic.