Fatto matematico: 6547 is the number of binary 4×4 matrices with no row or column containing 3 consecutive 1's.
Trivia: 6547 is an uninteresting number.
Data storica: December 3rd is the day in 1912 that Bulgaria, Greece, Montenegro, and Serbia (the Balkan League) sign an armistice with Turkey, ending the two-month long First Balkan War.