Dubai is set to open the world’s tallest building amid tight security today, celebrating the tower as a bold feat on the world stage despite the city-state’s shaky financial footing. The height of the Burj Dubai remained a closely guarded secret on the eve of its opening.

At a reported height of 2,684 feet, it long ago vanquished its nearest rival, the Taipei 101 in Taiwan. The building boasts the most stories and highest occupied floor of any building and ranks as the world’s tallest structure, beating out a television mast in North Dakota.

“We weren’t sure how high we could go,’’ said Bill Baker, the building’s structural engineer. “It was kind of an exploration. . . . A learning experience.’’ Baker, of the Chicago architecture firm Skidmore, Owings & Merrill, said early designs had the Burj edging out the previous record-holder, the Taipei 101, by about 33 feet.

The Taiwan tower rises 1,667 feet.The Burj’s developer, Emaar Properties, kept pushing the design higher even after construction began, eventually putting it about 984 feet taller than its nearest competitor, Baker said. He was keeping quiet about the exact height.

Dubai’s ruler will open the tapering metal-and-glass spire with a fireworks display this evening. Newspapers quoted Major General Mohammed Eid al-Mansouri, head of the protective security and emergency unit for Dubai Police, as saying more than 1,000 security personnel will be deployed.