The three countries with the highest Muslim populations are, in order:
1. Indonesia
2. Pakistan
3. India (though it's a non-Islamic country)
Iran
India has the world's second largest population, after China.
The world's largest country by land area is Russia.
China has the largest population in Asia with over 1.4 billion people.
Russia is, geographically, the largest country in Europe, as well as the largest country in the world. Even if you only count the part of Russia that's in the European continent Russia is still, by far, the largest European country.
The worlds largest population is Indonesia.http://islam.about.com/od/muslimcountries/a/population.htm
Indonesia is the country of largest Muslim population (203 million Muslim as of year 2009), followed by Pakistan (174 million), India (161 million), Bangladesh (145 million) and Egypt (79 million).
Thailand
China
Iran
China has the largest population in Asia with over 1.4 billion people.
India has the world's second largest population, after China.
Pakistan
Spain
The world's largest country by land area is Russia.
India
Indonesia - 231.5 million representing 3.4% of the worlds population