The population density of a certain region is 12 people / km2. When dividing what value by what value

The population density of a certain region is 12 people / km2. When dividing what value by what value, you get a value that expresses population density?

To determine the population density per square kilometer, the total population should be divided by the total area of the territory in which they live.

Let’s look at an illustrative example.
The population of Russia is 143.5 million people, and the total area of the territory is 17,100,000 square kilometers.
Under these conditions, the density of the population that lives on its territory will be.

143500000/17100000 = 8.4 people per 1 square kilometer.