Birdman -- $500,000 BDAY PARTY ... Champagne, Celebs, Hotties & Bugattis

Birdman's on a mission to throw one of the most insane 45th birthday parties known to mankind -- a "Half a Milly" bash -- filled with endless champagne, naked models, the entire Young Money crew ... and his $7 MILLION car collection.The party's set…

Charlize Theron Chelsea Handler Cheryl Burke China Chow