ATLANTIC CITY — Mariah Carey may be a pop diva, but much of the sold-out crowd at Borgata Hotel Casino & Spa treated her like she was a deity on Saturday night.

Constantly taking pictures and video, screaming at the top of their lungs in appreciation and holding up signs to express their devotion, Carey’s fans are undoubtedly loyal.

And they certainly have plenty of good reasons. Carey is to pop what Led Zeppelin is to rock, what Metallica is to metal and what Johnny Cash is to country.

Her resume doesn’t lie. The Long Island, N.Y., native scored 18 No. 1 singles in the United States, second only to The Beatles and ahead of Elvis. Her 12 studio albums have sold more than 62.5 millions copies in the U.S., and earned her five Grammy awards as well as the title of most successful artist of the 1990s in the U.S. by Billboard.

Yet here was the 40-year-old songstress in Borgata’s 2,200-seat Event Center. Like Madonna — arguably her only competition as the most popular female artist of all time — she should be playing arenas.

So why is she doing a mostly theater tour?

The truth is … she’s a bore. While Carey clearly has unbelievable pipes — her five-octave vocal range was on full display and flawless Saturday night — she has the stage presence of a slug. An attractive slug, but a slug nonetheless.

Surrounded by a nine-member dance team that was at worst clunky and at best average, Carey’s idea of being a headliner consists of standing on stage, singing her heart out and letting the dancers do all of the work.

For the fans who are content with hearing her belt out unbelievable vocals, it works. For casual fans looking for a good show, Carey is certainly not that kind of entertainer.

On the road for the first time since her 2006 comeback tour, “The Adventures of Mimi,” Saturday was Carey’s second stop on her “Angels Advocate Tour” to support her new album, “Memoirs of an Imperfect Angel.”

Carey, who made four costume changes but opened wearing a white dress partly made of feathers, rolled out a solid mix of her chart smashes, fan favorites and new tracks, showing her diversity and stellar range.

Although she pulled out songs that went all the way back to 1991, a large part of Carey’s 18-song set came from “Memoirs” and 2005’s “The Emancipation of Mimi.”

Particularly memorable tracks off “Mimi” included the Usher-like “Shake It Off;” “It’s Like That,” which fuses old-school hip-hop from Run-DMC; and “We Belong Together,” a No. 1 hit that cemented her career comeback.

All three of those tunes, as well as the fan favorite “Always Be My Baby,” had one thing in common: Jermaine Dupri, who co-wrote them and served as guest DJ at an afterparty at Borgata’s mixx nightclub.

Off “Memoirs,” her latest singles “Obsessed” and “H.A.T.E.U.” — Having A Typical Emotional Upset — seemed to get the biggest crowd reaction, while “Angels Cry” and “The Impossible,” which she dedicated to husband Nick Cannon, who also performed at a Borgata afterparty, landed flat.

Carey was not shy about pulling out the big guns either, including at least a half-dozen No. 1 songs, all memorable in their own way.

“Touch My Body,” off last year’s “E=MC2,” was simple pop at its best; “Heartbreaker” had the crowd on its feet; “Emotions” showed her fun, disco side and her ability to still hit every high note; and her signature “Hero” was a fitting finale.

Aside from her voice, there were other upsides. For the opener, Carey was lowered from the rafters on a giant swing. She drank Champagne and reclined on a couch while joking about her diva status during “Subtle Invitation”: “Do they expect me to stand up for the whole show? They call me a diva because … I guess I am one.” She threw in a cover of the Diana Ross smash “Love Hangover” to lead into “Heartbreaker.” And Trey Lorenz’ cover of Michael Jackson’s “Rock With You” was well done.

There also were some differences from her opening show at Madison Square Garden. Aside from “The Impossible,” she also offered “Honey,” the Latin-infused “My All” and one of the night’s best, “It’s a Wrap.” And she surprisingly did not perform “Fantasy,” one of her biggest hits and a show staple.

Carey certainly has had her share of ups and downs in a very public life that included her divorce from Columbia Records exec Tommy Mottolla, a well-documented emotional breakdown, the bomb of her movie “Glitter” and a period of dipping success. But she remains on top of the pop world for a variety of reasons: She keeps reinventing herself, she aligns herself with people like Dupri and she remains a stunning beauty.

But the main reason she’s still a superstar is that she’s way too talented to go away. If she could only amp up her stage presence, Madonna may even have something to worry about.

Contact Scott Cronick: