It's something over 200, which basically means that, for every possession you're in the game, you're scoring 3 pointers with and-ones, and the opposition scores nothing because you get a block or steal and a rebound.
With very small sample sizes, you can see those insane PERs show up. Errol Barron had that playing 23 seconds in his first game, where he got a rebound and hit a jumper.