I counted 37 floors. If there are 37 apartments per floor since the building looks square-ish (those would be some small apartments) and there are 2 rows (one on each side of the building), that is less than 3k apartments. If each had a family of four, that is less then 12k.
It doesn’t look to me like the kind of a building that would have this, but sure, maybe you could barely reach 20k is you squeeze people in like sardines.