Bill Cosby didn't stroll down an actual red carpet into prison, but he might as well have ... based on the treatment his team says he's getting in the maximum security prison he now calls home.

As we reported, Cosby is now at the Pennsylvania State pen at Schwenksville and in good spirits ... according to publicist Andrew Wyatt. The disgraced comedian was almost immediately transferred behind bars after Tuesday's sentencing, and Wyatt tells us staffers and guards were amazed to meet Cosby.

He described Cosby's Wednesday morning phone call to his wife, Camille, and how guards were hesitant to interrupt inmate NN7687.