You won Mega Millions? Congratulations! Now don't go broke

The Mega Millions jackpot is now up to $540 million, the biggest lottery jackpot in history, and it's sure to climb even higher before Friday night's drawing. Previously, the biggest jackpot was $390 million, won by two players in Georgia and New Jersey in 2007.

The odds of winning the Mega Millions jackpot are one in 175 million. If you're the lucky winning ticket holder, lottery experts say the first thing you should do is sign the winning ticket on the back, before you have a chance to lose it or have it stolen. Then, you should photocopy the ticket and lock the copy in a safe place.

As for investing your millions, maybe the first thing you should do after claiming your winnings is: nothing.

"No one says that you have to claim it immediately. I would seek professional counsel first, before making that decision," said Eric Long, a financial advisor with Edward Jones Investments in Myrtle Beach.

Long said you should start by getting investment advice from a financial planner and an estate planning attorney before doing anything with your jackpot.

Your first big decision will be whether to take your winnings in a lump sum or an annuity spread out over many years. Long said that depends on a variety of things.

"What kind of outstanding indebtedness do you have? Are you charitably inclined? What do you want to pass on to your heirs and family, what is your age? All of those factors come into play," he said.

You should find out the rate of return for the annuity plan, Long said. You may be able to get a better return by taking the lump sum and investing the money yourself.

If you have young children, Long advises you to set up trusts for them, so they wouldn't get a huge inheritance all at once.

"You can determine at what level over what time period that money is doled out in the event that you pass on before you've collected all of that."

Some studies have show up to one in three lottery winners declares bankruptcy after just a few years. Long said that's due to poor planning and some free spending. So, if you're the big winner, find a place to allocate your money safely, before going on a spree. "It makes sense to pay yourself first and then enjoy the winnings after that."

There are also taxes to consider. State and federal taxes will be withheld before you even get your winnings. You should count on at least a third of it going to the government.

The Associated Press contributed to this report.