Simon Property Group, Inc. (NYSE: SPG), also known as SIMON, an S&P 500 company heaquartered in Indianapolis, Indiana, is the largest developer of shopping malls in the United States. Simon Property Group, Inc. operates as a real estate investment trust (REIT) engaged in the ownership, development and management of high-quality retail real estate, primarily regional malls, Premium Outlet Centers, Mills landmarks, and community/lifestyle centers. Through its subsidiary partnership, it owns or has an interest in at least 380 properties in the United States comprising more than 258,000,000 square feet (24,000,000 m²) of gross leasable area in 39 states, plus Puerto Rico. Simon Property Group also holds interests in 52 European shopping centers in France, Italy and Poland; five Premium Outlet Centers in Japan; one Premium Outlet Center in South Korea and one Premium Outlet Center in Mexico. It currently has ownership interests in some of the most high-profile shopping malls in the world.