Powerball now at $620 million, while Mega Millions jackpot hits $1.6 billion. Do this if you win

The games continue: With no one hitting all winning numbers in Saturday's Powerball drawing, the jackpot has jumped to $620 million.

And after no one won the the top prize in Friday night's Mega Millions drawing, that haul has surged to a staggering $1.6 billion — the largest jackpot in U.S. lottery history.

Yet at some point, someone will get really lucky. As in really, really, really lucky.

Your chance of winning the Mega Millions jackpot, though, is pretty dismal: 1 in 302.6 million. Prior to last October, when changes were made to the game, it was 1 in 258.9 million.

With the odds of winning stacked against players, no one has hit that jackpot since July when a group of coworkers in California won $543 million.

For the Powerball jackpot, meanwhile, your chance of winning is 1 in 292 million.

Playing both lotteries The chance of winning both is at least 1 in 88 quadrillion (that's 88 followed by 15 zeros). The next drawings are Tuesday night for Mega Millions and Wednesday night for Powerball.

If you happen to beat the astronomical odds, here are some expert tips to avoid making a wrong move with your win right out of the gate.

Tend to your ticket

Make sure you have a safe place to store your winning ticket, like a lockbox or safe.

Also, the standard advice is to sign the back of your ticket. However, you might first want to check the laws of the state where you purchased the ticket.

Some states allow you to claim anonymously. Other states don't. Yet some might allow you claim the prize via a trust as a way to shield your identity from the public. If the ticket bears your name and not the trust's name, it could cause issues if you try to go that route.

To make sure you understand your options, it's worthwhile turning to experienced professionals before doing much of anything.

Enlist the help of pros

You should assemble a team of experts with experience in helping navigate lottery wins. That should include an attorney, a financial advisor and tax advisor.

"Make sure you're comfortable around each team member, and make sure they have the proper accreditation for their field," said certified financial planner Jim Shagawat, president of Windfall Wealth Advisors in Paramus, New Jersey. "You need a team around you to guard against being taken advantage of."

Someone on the team will need to serve as your gatekeeper. That is, they can field requests from moochers or scammers or even friends and family members who want a piece of your windfall.

Keep your win quiet

You might be so excited that your first instinct is to share your news far and wide. Bad move, experts say.

One of the best ways to protect your newfound wealth is to avoid letting too many people know about it. Of course, this can be difficult if you cannot claim your prize anonymously. Even if you can, though, it's still best to avoid sharing your exciting news with too many people.

"Obviously it may be impossible to keep this from immediate family, but news like this travels quickly," said Jason Kurland, a partner at Rivkin Radler, a law firm in Uniondale, New York. "Try to keep the circle of people who know as small as possible."

Past prize winners have discovered the hard way that long-lost friends and relatives can come out of the woodwork looking for loans or handouts. Scammers, too, have a way of zeroing in on lottery winners.

Mull over lump sum or annuity

You get to choose between taking your winnings as an annuity spread out over three decades or as a lump sum all at once.

For Mega Millions, the immediate cash option is $904 million. For Powerball, its $354.3 million.

Many experts recommend taking the lump sum, because if it's managed and invested properly, you could end up with more money over time than if you took payments spread out over several decades.

However, it's important to evaluate your own situation.

"If you know you have trouble with compulsive spending or know that certain family members will be after your money, you may want to go the annuity route," Shagawat said.