[dumb1224]

It's a common source of confusion. The administrative definition of a 'city' is the equivalent of its metropolitan area + all satelite 'towns' and their suburbs (including farm lands).

My hometown has a population of 3.4 million (prefecture level city or 3rd tier as people call it). But it has an area about 6000 km^2, easily reaching the total size of London. At its core the central town has roughly a population of 700,000. And there are 4 more towns after the central one, each has smaller villages and suburbs under them. People living in these towns wouldn't consider they are living in the same city.

[dumb1224]

Forgot to add context, my hometown is under zhejiang province (as different regions have different population structures).

[dumb1224]

I got the area wrong. Greater London is apparently 1500 km^2 so the total area of my administrative city is 4 times the size of that (with a total population of 3.4 mil)