Fatto generale: 56720 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 56720 is a boring number.
Trivia: 56720 is an unremarkable number.
Data storica: April 17th is the day in 1492 that Spain and Christopher Columbus sign the Capitulations of Santa Fe for his voyage to Asia to acquire spices.