Fatto generale: 17739 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 17739 is an uninteresting number.
Trivia: 17739 is a boring number.
Data storica: July 25th is the day in 1797 that Horatio Nelson loses more than 300 men and his right arm during the failed conquest attempt of Tenerife (Spain).