2:33 PM PT -- TMZ obtained the 911 call from Rich Homie Quan's death, and his girlfriend tells the dispatcher the rapper is not breathing and does not have a heartbeat.

She also revealed he was unresponsive on a couch in their home when she called 911 ... and started foaming at the mouth when she tried to move him.

Rich Homie Quan, a platinum-selling rapper from Atlanta, is dead ... TMZ Hip Hop has confirmed.

RHQ died Thursday in his Atlanta home ... according to his family and a rep for the Fulton County morgue.

Rich Homie Quan's family tells TMZ Hip Hop ... they are shattered and heartbroken by his sudden death. No cause of death has been reported and they're desperately searching for answers.

Born Dequantes Lamar in Atlanta, RHQ first burst onto the scene in 2013 with his instant classic hit, "Type of Way" ... and followed through with fan favorites in "Flex (Ooh, Ooh, Ooh)" and "Ride Out."

Rich Homie Quan later joined Young Thug on the Cash Money Records project, "Rich Gang" ... and was he was a frequent collaborator with his hometown homies, 2 Chainz and Jacquees.

The last time we spoke to him, RHQ ripped the current state of hip hop for its murderous lyrics and cookie-cutter song formats.

Rich Homie Quan was 34.

RIP