This is the Citi that never sleeps. One of the largest financial services firms known to man, Citigroup (also known as Citi) has some 200 million customer accounts and serves clients around the globe. It offers deposits and loans (mainly through Citibank), investment banking, brokerage, wealth management, and other financial services. Few other banks can equal Citigroup's global reach: In addition to Citibank, it owns stakes in several international regional banks and has more than 110 million Citi-branded credit cards in circulation. However, Citi has been selling dozens of underperforming and noncore businesses in the aftermath of the financial crisis in order to refocus on its original mission -- traditional banking.