Shanghai's permanent population is about twenty million.
Tips
usage
Chinese counts in 万 (10,000) units: 二千万 = 2,000 × 10,000 = 20,000,000 (20 million). In speech 两千万 (liǎng qiān wàn) is more common than 二千万 — 两 generally beats 二 in front of measure-like words. 二千万 sounds more written/formal.
mistakes
Don't read this as 'two thousand ten thousand' — Chinese 万 is the base unit for ten-thousands, so 千万 alone means 'ten million' (1,000 × 10,000), and 二千万 just doubles that to twenty million.
