Berlin attracts a lot of people from within Germany, and out. Germany takes in a lot of immigrants and refugees, and many of them live in Berlin.
Berlin in 2009 was estimated to have 100,000 to 250,000 non-registered inhabitants.
Of the city population, 54 percent were single-person households.
In 2014 the German capital registered a migration surplus of approximately 40,000 people.
In December 2015, 621,075 registered residents were of foreign nationality, originating from approximately 190 different countries.
Berlin has more foreign residents than KCMO has total residents.
As of December 2013 there were approximately 1,000,000 people (about 30 percent of the --City proper-- population) with an immigrant background living in Berlin, with significant differences in their distribution. The immigrant community is diverse, with Middle Easterners (including Turks and Arabs), smaller numbers of East Asians, Sub-Saharan Africans and other European immigrants, Eastern Europeans forming the largest groups. Since the accession of Romania and Bulgaria to the European Union there has been a Romani influx. About 70,000 Afro-Germans live in Berlin.
There are more than 25 non-indigenous communities with a population of at least 10,000 people, including Turkish, Polish, Russian, Croatian, Palestinian, Serbian, Italian, Bosnian, Vietnamese, American, Romanian, Bulgarian, Chinese, Austrian, Ghanaian, Ukrainian, French, British, Spanish, Israeli, Thai, Iranian, Egyptian and Syrian communities.
An estimated 200,000–350,000 Muslims reside in Berlin, making up about 6–10 percent of the population.
The three largest universities combined have approximately 100,000 enrolled students.
https://en.wikipedia.org/wiki/Demographics_of_Berlin