LOS ANGELES - Los Angeles city officials are preparing for massive crowds during Tuesday's public memorial for Michael Jackson at Staples Center, even though only 17,500 tickets are being offered to the public.

Assistant police Chief Earl Paysinger says anywhere from a quarter-million to 700,000 people may try to reach the arena, even though a wide area around Staples Center will be sealed off to those without tickets.

As of 5:30 pm Friday, more than 524,330 people had registered for tickets, said a statement from Jackson family spokesman Ken Sunshine.

AEG, the company which operates the Staples Center, also changed the registration rules to allow non-U.S. residents to register for the drawing, the statement said.

City Councilwoman Jan Perry strongly urged people to stay home and watch the memorial on TV.

The ceremony will not be shown on Staples' giant outdoor TV screen and there will be no funeral procession through the city.

But public safety officials appeared to assume their requests to stay home would have little effect.

Since Jackson's death, fans have flocked to Jackson sites from Los Angeles to his Neverland Ranch in rural Santa Barbara County.

Staples Center is offering the memorial tickets through an Internet lottery. Eleven thousand tickets are for the arena and 6,500 for the adjacent Nokia Theatre.

People who want tickets must register on the web at Staplescenter.com. After 6 p.m. Saturday, 8,750 names will be randomly selected to receive two tickets each. Notifications will go out Sunday.

After the ticketing details were announced on television, it became impossible to log on to the arena's website.

Brent Trueheart, 20, of Los Angeles, went online on his cellphone immediately after hearing the announcement.

"It kept saying 'service unavailable, service unavailable,' and finally it got through. So once it got through, I started celebrating," he said. "It feels real good."

No details were given about the actual memorial events.

The memorial comes as the country's second-largest city struggles with a $530 million budget deficit.

Perry said the cost of police protection for "extraordinary" events like the memorial is built into the Police Department's budget, but she still solicited help for "incremental costs."

Last month, donations covered about $850,000 of the city's $1 million cost for the Los Angeles Lakers' NBA championship parade. Critics had blasted the idea of using city money when it is considering layoffs to close its budget gap.