A Gold Coast couple are $53 million richer after winning half of Australia's biggest ever lotto draw.

The middle-aged couple and a South Australian punter were the only winners in the Oz Lotto $106 million first division prize drawn on Tuesday night.

Golden Casket Lottery spokeswoman Karen Anning said the couple, who wanted to remain anonymous, would go to work on Wednesday despite their riches.

"It is business as usual for them today. They are going to work," Ms Anning said.

"They said they had to check their numbers multiple times last night.

"When they got the call this morning solidifying their winnings, they said `I was hoping to hear from you this morning'."

She said their winning ticket was a jumbo quick pick from Lucky Mermaid News agency on the Gold Coast.

"They are tossing around ideas on how they will spend their money," Ms Anning said.

"They want to help out family and donate money to some charities."

Meanwhile, an Adelaide battler says he's "numb" after winning $53 million in the record Oz Lotto draw.

The man, in his 40s, reportedly purchased the winning ticket at a cafe at the Queen Elizabeth Hospital.

"I'm numb and quite frankly I have no idea how I'm ever going to sleep again," the man told SA Lotteries.

"I never expected to win and certainly never expected to win more than $50 million."

The man, from the blue collar western suburbs of Adelaide, watched his numbers drop on the televised lotto draw.

The Adelaide winner registered his winning entry with SA Lotteries and was contacted within hours of the draw.

"I just watched the draw, matched three numbers and the other four numbers just fell into place," he said.

"I couldn't move, I couldn't react, I couldn't do anything but sit there and stare at my ticket."

The man told SA Lotteries he would share his prize with family members and charities.

Another 60 people will each get more than $33,000 from the second division pool.

The Tuesday night jackpot draw originally set for $90 million was pushed up by a surge of late entries, taking the first division prize to $106.548 million and the total prize pool to $177.422 million.

Meanwhile, a leading mathematician says based on the maths, it is not surprising two people shared the $106 million jackpot.

Nigel Bean, professor of applied mathematics at the University of Adelaide, said that with 45 million possible combinations, the chance of picking the winning numbers was similar to picking a particular playing card from decks stacked 16 kilometres high.

But he said the chances of there being two winners depended largely on how many entries were involved.

The more entries, the bigger the likelihood of there being multiple winners.

"There are 45 million possible combinations (of numbers) and well over 10 million tickets bought," Professor Bean said.

"If you just look at it, on average you would have expected at least two people to have chosen each combination.

"So if that is true, then there would be two winners."

Professor Bean said determining the exact odds of getting two winners would also require information on how people chose their numbers and that would take some more detailed calculations.

But despite knowing just how badly the odds were stacked against the players, the mathematician admitted to having an interest in the draw, with his wife holding a ticket.

Needless to say, he wasn't the Adelaide winner who shared in the first division prize pool with a Gold Coast couple