The drawing is set for 10 p.m. Friday. And while people in Chicago and across the nation are lining up to purchase tickets, the chances of getting struck by lightning are 50 percent better.
"I don't think I'll get struck by lightning. I'm going to hit this lottery. I'm going to hit it and I'm going to win! Then I'm going to take care of my mom and do all of the things I was speed to do," Patricia Lewis, Mega Millions player, said.
"If you buy a ticket you have an absolutely equal chance of winning, and all it takes is a great deal of luck," Michael Jones, superintendent of the Illinois Lottery, said.
The jackpot jumped Friday, reaching $640 million by 11 a.m. And that number could continue to grow.
Should someone match the numbers and collect the lump sum, after federal taxes the winner gets about $275 million. Then there's the 5 percent that goes to the state, and $18 million would certainly help out cash-strapped Illinois.
Craig Minnick is a CPA and lawyer with Horwich Coleman Levin who is currently working with a recent big-money winning lottery couple. Their lifestyle is changing, so has their phone number. But they have a plan despite predictable aggravation.
"All of a sudden, you have friends you have talked to are friends again, family that hasn't been involved with you previously are now involved," said Minnick.
A Loop newsstand has hit a much smaller jackpot before -- selling a $3 million winning Lotto ticket. Store owners and customers hope lightning will strike twice there.
Lottery officials say whoever strikes it rich should sign the back of the ticket and consult a tax attorney right away.
The Illinois Lottery's website went down briefly Friday afternoon but is back up.
Mega Millions lottery is played in 42 states- including Illinois, as well as in Washington, D.C., and the Virgin Islands.