According to the Istanbul Metropolitan Municipality's website, the city has a population of 12,573,836 residents (2007).
In the last 50 years, 11 million people have migrated to Istanbul. Istanbul has 32 counties and the most populated one is Gaziosmanpasa (not a touristic destination) with a little over 1 million residents. Kadikoy is the 4th most populated and is the home of the majority of Istanbul's natives. Adalar is the least populated with only 10,000 residents.