Fatto generale: 12891 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 12891 is an unremarkable number.
Trivia: 12891 is an unremarkable number.
Data storica: April 17th is the day in 1797 that Sir Ralph Abercromby attacks San Juan, Puerto Rico in what would be one of the largest invasions of the Spanish territories in America.