598,200 citizens, that's the same population as Taiz in Yemen, but this is in 29 and a half square kilometres. Ta'izz, as it iz also known, is 10,677 km²
Macau is a dependent territory, included in with countries when counting population, it is down at 168th in terms of population size.
Then there is Vatican City which is positively tiny in population. Along with Monaco - the micro states aren't known for their numbers so much as the way they pack them in.
China has 142 people per square km. This is the same as The Gambia and Cyprus. Gambia has a population of 1.791 million, Cyprus 1.129 million. That's million, not billion.
China and Russia are very large countries with large natural features so there are deserts and forests to escape people. Given Bangladesh's placement in both measures, it is the land most likely to be full of people.
In fact, that's what this list below affirms. I still haven't got my head around what distinguishes the most populated countries: how is this determined in contrast to the countries with the highest population and those with the most inhabitants per square kilometre. It must be an amalgam to signify those countries that are both crowded and numerous, if that makes sense.