General fact: 51607 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 51607 is a boring number.
Trivia: 51607 is a boring number.
Historical date: April 17th is the day in 2006 that Sami Hammad, a Palestinian suicide bomber, detonates an explosive device in Tel Aviv, killing 11 people and injuring 70.