The record $640 million lottery prize that sent the United States into a gambling frenzy reportedly had at least one winner early on Saturday as local media said the winning ticket had been sold in the state of Maryland.

The winning numbers -- 2, 4, 23, 38, 46 with Mega Ball 23 -- were announced here at 11:00 pm (0300 GMT Saturday).

There has been no official announcement from Mega Millions lottery yet.

MSNBC television cited an unnamed Maryland lottery official in reporting the news. The Washington Post, using similar sources, said the winning ticket had been sold in Baltimore County.

However, it was not immediately clear if the Maryland ticket was the only one to win the gigantic jackpot.

Experts warned it could be days or even weeks before somebody showed up to claim the prize as winners usually tend to hash out all the legal issues with their lawyers before taking that step.

The chance to get suddenly very, very rich -- even if it was only a one-in-176-million chance -- had sparked feverish ticket sales at convenience stores and news kiosks across the United States.

There was plenty of fantasizing too on the airwaves and in newspapers about life after winning the monstrous jackpot -- a fantasy all the more powerful in a country with a weak jobs market and still spooked about recession.

The tickets made it unequivocally clear: this was nothing less than "the world's largest jackpot."

But it really was a fantasy: the chances of scoring the winning number weren't the same as being killed by lightning -- they were considerably lower.

The jackpot hit a record level because no one had matched the magic five numbers and Mega Ball since January 24 -- a full 18 draws with no winner.

Given the pace of ticket buying, the jackpot climbed inexorably higher, and New York Lottery spokeswoman Carolyn Hapeman told the New York newspaper Newsday late on Friday that tickets for the mega jackpot were selling at the unprecedented rate of $4 million per hour.

As the Kansas City Star helpfully pointed out, this was the kind of money that would get you a Boeing 787 Dreamliner and a private island in Thailand or, say, a quarter share in a nuclear-powered attack submarine.

In New York, customers cramming into Midtown News, a hole-in-the-wall newspaper shop that sells the $1 tickets, had more modest dreams.

"If I won, I'd retire in New Zealand, because there are more sheep than humans there. Here in New York, there are too many people," said Romanian immigrant Cosmin Barbos, 37.

Barbos, who does maintenance at a Manhattan law office, said he'd give most of his fortune to charity. Roger Sierra, a 32-year-old chef, said he'd give half.

"That's a promise I made, and I'd help my family. I'd buy a restaurant and we'd have food from all over the world -- French cuisine, American, steaks."

Although tickets cost only $1, the odds were so long that snapping them up in bulk would be of little use.

Organizers also cautioned people about going too far.

"Although most people can play Mega Millions and other lottery games without ill effects, there are some people for whom gambling of any sort can be addictive and very damaging. Like other addictions, gambling addiction is a treatable disease," the lottery's website advises.

Mega Millions is played in 42 US states plus the national capital Washington and the US Virgin Islands. Foreigners can play, too, but they must be in the United States.

The lucky winner gets to choose between an immediate cash option or the full amount disbursed over 26 annual payments. The prize will then take a severe knock in federal and state taxes.

The previous US record draw, in 2007, was $390 million.

US media were quick to offer advice, with the Los Angeles Times providing locations of California ticket vendors that have sold winning tickets in recent lotteries. CBS gave the sober suggestion of hiring an investment adviser.

The New York Post, meanwhile, devoted an entire page to demonstrate that the premise of money making you happy does not always stand up.

"Winners beware!" the Post headline said over profiles of four seemingly lucky Americans who went "from jackpot to jack squat."

These included the cautionary tale of Jack Whittaker, who won $315 million in 2002 and lost the lot to thieves and hard living, while his daughter and granddaughter both died from drug overdoses.