The Powerball jackpot — the largest in U.S. lottery history — is up to $700 million.

No tickets sold for Wednesday’s half-billion-dollar jackpot matched all five numbers plus the Powerball so the jackpot initially climbed to $675 million then went up again on Thursday, surpassing the previous all-time prize of $656 million for a 2012 Mega Millions game.

A Powerball spokeswoman said it was “very unlikely” the jackpot would go as high as $1 billion.

“Given that we are in uncharted territory, we are keeping an eye on sales . . . and will adjust the jackpot accordingly,” spokeswoman Kelly Cripe said.

Typically, when jackpots are so large, better-than-anticipated ticket sales generate “bumps,” or significant increases in the grand prize.

It happened three times for Wednesday’s Powerball, which initially was announced as a $400 million jackpot after no winning tickets were picked for the Jan. 2 drawing.

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On Tuesday, the jackpot had “bumped” to $450 million; less than 24 hours later it bumped twice more, to $500 million and then to $524 million.

Saturday’s Powerball prize is worth a lump-sum payment of $428.4 million, before taxes and withholding.

Wednesday’s drawing wasn’t a total loss for players. Nationwide, 14 tickets matched the five numbers but missed the Powerball; those tickets are worth $1 million apiece and include one sold in New York, at a food mart in upstate Fredonia.

The game is played in 44 states, Washington, D.C., Puerto Rico and the U.S. Virgin Islands.

Finally, the chances of winning? One in 292,201,338.

With Patricia Kitchen