Fatto matematico: 6620 is the number of 11-ominoes that tile the plane.
Trivia: 6620 is an uninteresting number.
Data storica: February 14th is the day in 1831 that Ras Marye of Yejju marches into Tigray and defeats and kills Dejazmach Sabagadis in the Battle of Debre Abbay.