1 Ric Olie: Coruscant. The entire planet is one big city.
1 Anakin: Wow! Let's see: population density of 50,000 per square kilometre...
2 Anakin: That's 10¹⁴ people and no arable land. You'd need to import the entire output of 10,000 agricultural planets to feed them.
3 Anakin: At a cargo capacity of 2,500,000 metric tons each, you need 80,000 Super Star Destroyers delivering fresh produce every day.
4 Ric Olie: Anakin, has anyone ever told you you're just an annoying little kid?
4 Jar Jar: Meesa agree...

Yes, that cargo capacity is a canonical figure, after correction for misprinted data that made the cargo capacity ten times less (and would have subsequently required Coruscant to use ten times as many ships to deliver food).

Do not think about what they do with all the sewage.

---

2013-01-22 Rerun commentary: 50,000 people per square kilometre is just an estimate I pulled out of thin air. Well, I estimated it as moderately higher than the highest population densities seen on Earth, for which Macau clocks in at just under 20,000. A high-tech place like Coruscant seems like it has giant buildings and layer upon layer of crawling undercity everywhere, so 50,000 seems plausible, at least in small localised regions. Applying that to the whole planet is really just artistic licence for the sake of this comic.

Canonically, Coruscant's population is supposed to be around the one trillion mark (10¹², a US trillion). So that'd be a mere 500 people per square kilometre.

It would also merely be the entire output of 100 agricultural planets to feed them, and 800 super star destroyers delivering food every single day. Much more plausible.