Or is that for each individual resident? Any advice on additional roommates? Is more the merrier and the cheapest? What should I keep in mind when looking for an apartment?
You and your roommate(s) will agree on how much rent each of you will pay each month. The landlord is not part of your agreement. Each resident who signs the lease is in reality responsible for the entire amount of rent. It is up to you and your roommate(s) to agree on how much each one of you is going to contribute.
In the US the rent quoted is the total for the apartment or house listed.
I hope you plan to see the apartment in person before signing any contracts on it.
If you have never rented before you may want to consider looking for the cheapest 1 BR you can find. You might have trouble finding/keeping a roommate. You might have trouble qualifying for a more expensive apartment (like 2BR) on your own & if the roommate takes off, you are still obligated to pay the full rent.