Washington rolled out its red carpet for the Bullets yesterday - a royal rug that was more than seven miles long lined by tens of thousands who cheered and reached out to touch their heroes.

From the Capital Centre to the White House, the new National Basketball Association champions took their triumphal ride along the horse-dotted countryside of Prince George's County, through the crowded housing projects and highrise apartments in the eastern end of the city, along the tree-lined streets of row houses on Capitol Hill, and past the office buildings on Pennsylvania Avenue downtown to rallies and ceremonies at the District Building, the White House, U.S. Capitol and Robert F. Kennedy Stadium.

In a governmental capital where broad avenues, visits by heads of state and the pomp of presidential inaugurals are commonplace, this was a uniquely spontaneous and personal small town celebration.

Every community and neighborhood through which the 25-car cavalcade moved had its own Main Street along the Central Avenue-East Capitol Street-Pennsylvania Avenue route, and each was overflowing as nearly a hundred intersections were inundated with cheering fans.

Mechanics and construction workers in their hard hats stopped work to watch the motorcade as it moved east from the Capital Centre arena along Central Avenue in Prince George's County. Senior citizens hung over the balconies and waved handkerchiefs at Capitol View Plaza. A gray-haired man in a business suit stood on one corner and shouted, "EEEEEEEE!!!" at the top of his lungs as Bullets star Elvin Hayes rode past.

The players, coaches and Bullet team staff reacted by making themselves physically accessible to as many of their fans as possible. From perches on the roofs of cars, they reached out to touch the extended hands of thousands who crowded close around them the length of the procession. Sometimes they recognized faces faces and called out names in the crowds.

At the rallies at the Capital Centre, District Building and RFK Stadium, they plunged into the milling throngs, allowing themselves to be grabbed and hugged by demonstrative admirers. Hundreds of autographs were signed on crumbled pieces of paper, playground basketballs and newspaper sports pages. Beaming Bullet owner Abe Pollin held aloft the gleaming gold championship trophy.

It was like a slow-moving roller coasted that undulated up and down hills, along Central Avenue and East Capitol Street, with each neighborhood crowd breaking into its own squeals and screams as the first red lights of the police escort of the often-delayed motorcade came into view.

"This town's waited 36 years for a world champion in any sport," said Carolyn Gillum as she stood across the street from the Capitol View Shopping Mall in far east Washington. "We can wait 36 minutes if they're a little late."

For one extraordinarily sunny, mild and unpolluted June day in the nation's capital, politics took a back seat as the mayor, a county executive, senators, congressmen, and the City Council climbed on the round ball bandwagon. Even the president of the United States posed for pictures with "The Fat Lady" and dribbled a basketball in the East Room of the White House.

"We can't believe this," said a jubilant Jerry Sachs, the Bullets vice president, heaving in the crush of the crowd that pressed up onto the steps of the District Building downtown. "This is the most exhilarating experience of our lives.

"Black, white, old, young, fat, skinny . . . everyone was along that ride. The Bullets are both proud and privileged that we can just be a unifying force in this community."

Kevin Grevey, the Bullets star guard, walked down the driveway of the White House shaking his head and saying, "I can't believe all this is happening."

The most personal and intimate of the gatherings was the first of the day at the Bullets home, Capital Centre, where 3,000 people chanted "We are the champions." They exchanged sophisticated critiques of the Bullets' basketball rebirth and some argued over who had been a Bullets fan the longest.

"We are the No. 1 team in the world," Bullet Larry Wright told the crowd before the cavalcade started off for Washington at 3 p.m. "If there's a cure for what we've got, I don't want it."

At the end of their seven-mile love-in, the Bullets pushed and smiled their way up the steps of the District Building where a crowd of more than 5,000 cheered so insistenly that Mayor Walter E. Washington's congratulatory speech was mostly drowned out. Officials at the District Building called the gathering the largest non-inaugural gathering in that square since VJ day at the end of the World War II.

Next, as the 5 p.m. rush hour crowd blew car horns in celebration outside, President Carter and First Lady Rosalyn Carter greeted the champions at the White House. They were each given a blue T-shirt emblazoned with the team's playoff slogan: "The opera isn't over 'til the fat lady sings."

"I wish I had thought of that during 1976," the president said. "There were a lot of times during the 1976 campaign when I thought the ball game was over."

On the Capitol steps the Bullets were greeted by more than a dozen members of Congress.

"These are the lean men who made the Fat Lady sing," praised Sen. George McGovern (D-S.D.) The ceremony there ended with a not-to-fat lady singing, "We are the champions of the world," which was drowned out by chants of "We're No. 1."

Though sundown inevitably brought a fizzling-out of the day's orderly jubilation, the finale - a free public gathering outsdie RFK Stadium - was a mild disappointoent.

The large, young and slightly unruly crowd of about 5,000 heard nary a word the Bullets said as cheers of "EEEEEEE" and "We're No. 1" obliterated worrds of the speakers. When the youngsters came close to swamping the makeshift platform, the Bullet players were taken inside the stadium for safety.

It all began about 1 p.m. by which time nearly 3,000 people were holding a leisurely party at the Capital Centre. For the last time all day the Bullets could walk slowly, looking in their fans' faces without worrying about being swamped.

Seven salesman, frantically hawking barrels of Fat Lady T-Shirts, looked up as the mammouth Wes Unseld passed.

"Hey, Wes," called out one. "What size do you wear?"

"About a medium-small," grinned the 270-pound captain.

As Unseld stepped out of the Centre into a brilliant summer day more suited to pollen and hay fever than Pollin and Bullet Fever, fans pounded his broad back and pumped his hand.

"Just look at this, Wes, please," pleaded Patricia Hall.

Her sign read: "Wes for President CJ (Charles Johnson) for Secretary of State. E (Elvin Hayes) for Everything. Bobby D. for Anthing."

"You got that just right," said Unseld, spending one of his rare smiles.

The day's gathering of hoop sophisticates took place earlier in the Centre's Capital Club where Bullet players, former pros, local college and high school coaches and season ticket holding gathered to observe the NBA draft that was going on via telephone hookup.

"Six months ago I was ready to break up this whole Bullet team and trade the bums to the four corners of the earth," laughed Bernie Farkas, a Bullet season ticket holder since the day they came to Washington five years ago.

"They've disappointed this area for so many years. All you heard was 'Great team, great team,' then they'd get verge of a championship (in '71 and '75) only to fold up completely.

"They lost a lot of fans and I was one of them. Now, when nobody thought they were on the verge of anything, they win the championship. They've won me back and a lot of other people," too,"

"This day will sustain me throught 10 years of hard times," said Roger Comer.

The official Prince George's County greeting outside was kicked off by County Executive Winfield M. Kelly Jr. crowing, "What a beautiful day in beautiful downtown Largo."

"What about building the Centre an access road," questioned a leather-lunged fan.

The Bullets were most relaxed before this laid-back group of popsicle-lickers and air-horn tooters.

"You are the No. 1 team in the world," glowed owner Pollin. "Everyone of you owns a part of this trophy."

Coach Dick Motta, whose motif all day was to duck most attention, made his longest speech of the afternoon: "Here are a great bunch of guys. Let's introduce 'em."

Eleventh-man Phil Walker was introduced first, but was almost too embarrassed to speak. Fellow rookie Greg Ballard, however, was poised as usual, saying, "Now that we're world champions, let's just wear it, and wear it well."

Both veteran Johnson and Mitch Kupchak showed wry sense of humors.

"We couldn't have done it in an empty building," said Johnson, who paused and then added. "You people drove us to the top." In an adjoining parking lot was the helicopter that had first brought Johnson to the Centre as a free-agent castoff several months ago.

As the 6-foot-11, 23-year-old Kupchak approached the platform microphone, the crowd started yelling, "Dive, Mitch, dive. Dive on the mike."

"I never thought I'd want to be cheered by a Maryland crowd," said Kupchak, who played at Maryland's arch-rival, North Carolina.

"We never booed you, Mitch," pleaded a fan, "Honest."

Bullet veterans Hayes and Unseld were obviously the most moved. Hayes, so often the designated goat in the past, said, "You pushed us. You people made us what we are." Hayes, who conquered a childhood stutter years ago, was so choked up that his stammer returned. But it only made the crowd cheer his heart-felt words louder.

About two hours later, the motorcade was met at 12th Street and Pennsylvania Avenue N.W. by the 100-member marching band from Howard D. Woodson High School, who high stepped in their red-black-and green uniforms and played the theme song from "Ricky."

It was not a day for the politicians at the District Building. Mayor Washington got a few scattered boos when he was introduced. Undaunted, the mayor presented Bullets owner Pollin with a hand-crafted key to the city - a memento ordinarily given only to foreign heads of state and heads of government. The mayor and City Council Chairman Sterling Tucker each presented proclamation declaring yesterday Bullets Day.

At the White House, about 150 staff members cheered as the team came into the East Room and presidential press secretary Jody Powell introduced the president.

Carter was given an autographed basketball, which he authoritatively dribbled half a dozen times and, endangering the crystal chandeliers hanging from the high ceilings, lobbed a shot up on the stage where the team was standing. Then the president posed for pictures, one of which was taken by Unseld's wife, who had brought the family camera.

Also contributing to this story were Washington Post Staff Writers John Feinstein, Donald Huff, Donald P. Baker, Nancy Scannell, Betty Cuniberti and Jack Eisen.