In college, prime numbers drove you to drink.

And they’ll do the same (minus the frustration) at Bar 721, a new lounge opening tonight on South Beach.

Despite its off-Lincoln location (the old Laundry space), the bar has a neighborhood feel, thanks to owners Dan Sehres (New Concept Video) and Martin Krediet (director of marketing at the always-hip Raleigh).

The dimly lit lounge — a modern spin on a retro living room — is outfitted with plush couches, faux fireplace, shag rug, and exposed brick wall. Completing the stylish basement facade: a pool table, Guitar Hero, and a flat-screen TV playing live concerts.

Expect rotating DJs, cocktails like the Martini 721 (Grey Goose La Poire, St-Germain, prosecco), and well drinks for less than $10.

Finally, a number you can live with.

Bar 721, 721 Lincoln Lane North, South Beach (305-532-1342).

Photo: Courtesy of Bar 721