Russia's 160 ethnic groups speak some 100 languages. According to the 2002 census, 142.6 million people speak Russian, followed by Tatar with 5.3 million and Ukrainian with 1.8 million speakers. Russian is the only official state language, but the Constitution gives the individual republics the right to make their native language co-official next to Russian.
Despite its wide dispersal, the Russian language is homogeneous throughout Russia. Russian is the most geographically widespread language of Eurasia and the most widely spoken Slavic language. It belongs to the Indo-European language family and is one of the living members of the East Slavic languages; the others being Belarusian and Ukrainian (and possibly Rusyn). Written examples of Old East Slavic (Old Russian) are attested from the 10th century onwards.
The Russian Language Center says a quarter of the world's scientific literature is published in Russian. It is also applied as a means of coding and storage of universal knowledge—60–70% of all world information is published in the English and Russian languages. Russian is one of the six official languages of the UN
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