Fatto matematico: 9151 is an uninteresting number.
Trivia: 9151 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Data storica: January 19th is the day in 1817 that an army of 5,423 soldiers, led by General José de San Martín, crosses the Andes from Argentina to liberate Chile and then Peru.