The previous top prize was $365 million won by ConAgra Foods workers in Lincoln, Neb., in 2006. Powerball is played in 42 states, Washington, D.C., and the U.S. Virgin Islands.
The prize may increase even more before the drawing. Tickets have to be purchased by 8:59 p.m. Wednesday.
The Mega Millions lottery holds the record for the biggest payout in U.S. history. In June 2012, a $640 million prize was shared among three ticket-holders.
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