General fact: 6720 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Mathematical fact: 6720 is an uninteresting number.
Trivia: 6720 is an unremarkable number.
Historical date: May 25th is the day in 1955 that First ascent of Kangchenjunga (8,586 m.), the third highest mountain in the world, by a British expedition led by Joe Brown and George Band.