Fatto generale: 17551 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 17551 is an uninteresting number.
Trivia: 17551 is an unremarkable number.
Data storica: January 19th is the day in 1883 that the first electric lighting system employing overhead wires, built by Thomas Edison, begins service at Roselle, New Jersey.