Michael Jackson would be happy to learn his former pet chimp, named Bubbles, is living the good life as an elder primate … according to the sanctuary that took him in.

Patti Ragan, director of the Center for Great Apes, tells TMZ … Bubbles has a lot of freedom at the sanctuary. He’s able to explore tunnels, build a nest under a tree, take daily midday naps and occasionally even paint!

Bubbles, now 41, is regularly checked out by a veterinarian and caregiver staff … and weighs in at 180 pounds. BTW, the lifespan for a chimp in captivity is between 50 and 60 years.

She goes on to describe Bubbles as a friendly chimp who interacts well with visitors and other animals … including fellow chimps Oopsie, Boma, Ripley, Kodua, and Stryker. We’re told Bubbles doesn’t show any signs of past abuse.

Though the sanctuary plays MJ’s music and videos for the chimps … Bubbles doesn’t appear to like Michael’s music over any other. So, despite their once fierce bond, the singer is long in Bubbles’ past.

Michael couldn’t keep Bubbles as a pet when the primate reached adulthood … first sending him to a trainer in 2003, before placing him at the sanctuary 2 years later.

As TMZ previously reported … Michael passed away 4 years later on June 25, 2009 — from acute propofol intoxication. According to Patti, the Center for Great Apes doesn’t plan on commemorating the 15-year anniversary of Michael’s death.

The Michael Jackson Estate has continued to care for Bubbles in the aftermath of MJ’s death … contributing to his annual care cost, which comes in at around $27K a year. Michael’s fan club also sends Bubbles several treats, including coconuts, mangos and blankets — which we’re told he likes to curl up in during his naps.

Michael’s attorney and family members have made an effort to visit Bubbles in recent years … where they’ve had nothing but sweet encounters with the primate.