The download size of the app is around 50MB, which includes two languages - English (UK) and Spanish (Latin American), including voice packs. You can download any of our other languages for around 6MB per language, and use that language in the map via typed or voice search (the only languages we don't currently support for voice are Mongolian, Swahili, isiXhosa, isiZulu, Afrikaans, and Bahasa Indonesia. We hope to add these languages for voice search at some point).
The technology is based on an algorithm rather than a massive database, which is why it can fit on your device. A database of 57 trillion addresses would be many, many terabytes in each language!