Atlanta is the capital and most populous city in the state of Georgia as well as the urban core of one of the fastest-growing metropolitan areas in the United States. With a population of 537,958, Atlanta is the thirty-third largest city in the United States, and the 28-county Atlanta Metropolitan Area is the 8th-largest such region in the United States, with more than 5,376,285 residents. The Atlanta Combined Statistical Area, home to 5,729,304 people, is the most populous in the Southeastern United States, and the city is considered the central metropolis and the unofficial capital of the region. Considered a top business city and transportation hub, Atlanta is the world headquarters of The Coca-Cola Company, AT&T Mobility, and Delta Air Lines. The surrounding area contains additional corporate headquarters, including Home Depot and UPS. Atlanta has the nation's third largest concentration of Fortune 500 companies, and more than 75 percent of the Fortune 1000 companies have a presence in the Atlanta metropolitan area. Hartsfield-Jackson Atlanta International Airport, which is located seven miles south of downtown Atlanta, is the world's busiest airport.