United States is 20,789,984 times larger than Vatican.
The United States of America, commonly referred to as the United States, America, and sometimes the States, is a federal republic consisting of 50 states and a federal district. The 48 contiguous states and Washington, D.C., are in central North America between Canada and Mexico. Wikipedia
Area: 0 km2 World Factbook
Population: 842 (July 2014) World Factbook
Vatican City, officially Vatican City State, is one of the last six remaining absolute monarchies whose territory consists of a walled enclave within the city of Rome. It has an area of approximately 44 hectares, and a population of around 840. Wikipedia