The Broadway musical "Nine," based on the movie "8 1/2," is a symphony of numbers. Six producers, six years of preparation. Final cost: $2.75 million, including several trips to Italy to obtain rights to Fellini's movie, and salaries for 700 people to make costumes and three people to train the doves. All topped off by an 11th-hour push for tonight's opening, which just meets the deadline for this year's Tony nominations.

"Nine" is also a cacophony of disasters: a $60,000 prize forfeited for the dream of a Broadway production; the loss of a major backer, Paramount Pictures, just when that dream was about to become reality; the jailing of a leading Italian producer the day after a team of lawyers had flown to Rome to obtain rights.

The story of "Nine" is basically the same as the story of "8 1/2": Guido Contini, played by Raul Julia, is an acclaimed movie director who cannot find the inspiration for his next movie (it is based roughly on Fellini's life, and was called "8 1/2" because it followed the director's eighth movie.) Guido is harried on every side by the women in his life, whom he loves but cannot control, and he escapes from his pressures through flights of fantasy into his childhood. The story is held together, in large part, by the costumes, which move, in succession, from green to red to white, the colors of the Italian flag. There is also one black scene and one pink scene, in which the women emerge en masse wearing 18th-century costumes decorated with bubbles, feathers and schools of fish.

Today "Nine" has an illustrious production team, including James M. Nederlander among the producers, Tommy Tune as director and choreographer, and Raul Julia in the lead, the only man in the cast, which also includes 21 women and four boys.

But when it began at Yale in 1976, it was the farfetched project of Maury Yeston, a young music professor. Yeston, collaborating with Mario Faratti, who translated the "8 1/2" script from the Italian, composed the lyrics and score to "Nine" and for several years unsuccessfully approached many producers. Two years ago at the Eugene O'Neill Festival in Waterford, Conn., the script won a $60,000 grant, the Richard Rodgers award for a nonprofit production. It also attracted the attention of Michel Stuart and Harvey Klaris, two would-be Broadway producers looking for a production. Yeston, aiming for Broadway, gave up the $60,000 and gritted his teeth for the struggle to follow. "I really didn't know what I was getting into because I've never been there," he said during previews as he worked on a new song to the score. "We must have changed this production at least a hundred times."

The big break was immediately followed by a bitter disappointment. Last December, Paramount Pictures, which had started a theater production department, put up $150,000 for a workshop--a dry run without costumes or sets--with the understanding that it might provide half or all of the financing after assessing the production. Playwright Arthur Kopit rewrote the book for this workshop. Even so, officials at Paramount decided they couldn't continue with the production.

Dan Sherkow, spokesman for Paramount, says that the main objection was the $2.75 million needed to stage the production: "Everyone thought it was good, but for that much money we had to be absolutely convinced it was going to be a blockbuster."

Rehearsals and an extended preview had already been scheduled to prepare the show to open in time for Tony deadlines. A nomination or, better, an award would doubtless secure the musical's position and ensure a long run, the creators figured. Michel Stuart, who had to raise the missing money, now dismisses the task: "Money doesn't scare me," he said. "A few extra zeros at the end of a five means little to me."

A few of the backers stayed with the production after Paramount withdrew. One reason was Tommy Tune, the boy wonder of Broadway, a young giant in stature and height (he's over 6 feet 5 inches), who had just agreed to direct and choreograph.

Tune added clout to the production. He and Stuart had a successful off-Broadway production, "Cloud Nine," which is still running. Tune also won a Tony Award last year for the choreography of "A Day in Hollywood/A Night in the Ukraine," and he had two other hits to his name, "The Best Little Whorehouse in Texas" and "The Club," an off-Broadway production.

But other problems followed. Before any of the backers would release the money they'd agreed to put up, they wanted to secure all rights to "8 1/2," including subsidiary rights. To that end, a team of lawyers flew to Rome in February to get Fellini, his three collaborators and the Italian company Rizzoli International to sign a new contract. "It was chicken and egg. We needed the rights to get the money and the money to start rehearsals and the theater was already lined up for May 9," said Klaris.

Rizzoli, however, was in receivership, because some of its officials were involved in a neo-fascist plot to overthrow the Italian government, and the day after the lawyers arrived, Rizzoli himself was jailed. Without the necessary signature, the lawyers returned to New York, and the production ground to a halt.

Klaris flew back to Rome in April, and after long negotiations with Fellini, persuaded the Italian director to appeal to Rizzoli, who by then was out of jail. On April 16, Rizzoli signed the agreement, and on April 18, rehearsals for "Nine" resumed.

With less than a week before the first preview and less than a month before the opening, the cast and crew worked around the clock. Dance numbers had to be redone to accommodate the constraining costumes and the narrow path around the orchestra pit. Several cast members felt they might fall into the pit. "We really had to teach people how to maneuver," recalled Stuart.

The 21 women in Guido Contini's "stable" were selected for their various and voluptuous shapes. Each one needed a maid to keep her costume changes in order. "You cannot believe," said designer William Ivey Long, "that there are that many different sizes and shapes. Some of the plumper women would lose weight in between fittings and Tune would have to reassure them that they were all right heavy, saying, 'I love you for your bodies.' "

During previews, the crew still hadn't solved the problem of the doves, meant to be released in mid-scene and to fly in tight formation across the theater. Three trainers cajoled and cooed at the birds, which had flown off in several directions, attempting to coax them out of the rafters. As of last week, the plan had changed to let them go as the curtain came down.

"If they can't make it," said Stuart, "we'll recast them. After all, this is Broadway."