Denmark is 640 times larger than Arlington County, Virginia.
Area: 43,094 km2 World Factbook
Population: 5,569,077 (July 2014) World Factbook
Denmark, is a Nordic country in Northern Europe, located southwest of Sweden and south of Norway, and bordered to the south by Germany. The Kingdom of Denmark comprises Denmark and two autonomous constituent countries in the North Atlantic Ocean, the Faroe Islands and Greenland. Wikipedia
Area: 67 km2 calculated
Arlington County is a county in the Commonwealth of Virginia. It is coterminous with the U.S. Census Bureau-designated place of Arlington, which is the second-largest principal city of the Washington, D.C. metropolitan area. Wikipedia