According to the Pew Research Center, only 20 percent of the world's 1.6 billion Muslims (as of 2010) live in the Middle East and Northern Africa, the regions most closely associated with Arab people. The place with the most Muslims, interestingly, is the Asia-Pacific region, which is home to nearly two-thirds (62 percent) of all Muslims [source: DeSilver and Masci].
More Muslims live in Indonesia (209 million) than any other single country, followed by India (176 million) and Pakistan (167 million). Egypt has 76 million Muslims, putting it sixth on the list, but No. 1 among Arab-majority countries [source: Pew Research Center].
The reason many Westerners associate Islam with Arab-majority countries is that the density of believers is highest in that region. In the Middle East and Northern Africa, 93 percent of all 341 million inhabitants identify as Muslim. Compare that to only 24 percent in the Asia-Pacific region [source: DeSilver and Masci].
Even though many more Muslims live outside of Arab countries and practice non-Arabic interpretations of Islam, they get far less attention from Western media than Muslims from the Middle East.