How should I invest the money?

To build a nest egg large enough to see you through retirement, which may last 30 years or more, you'll need the growth that stocks provide.

The stock market returned 10.02% a year on average between 1926 and 2015, versus just 5.58% for bonds, according to research firm Morningstar. Given stocks' superior returns over the long haul, most financial advisers recommend that investors whose retirement is more than 20 years away hold at least 3/4 of their portfolios in stocks and stock funds.

Of course, a stock-heavy portfolio can give you some hair-raising moments (or years). For example, during the 2007-09 bear market, U.S. stocks lost 50.17% of their value - and it took the market more than three years to recoup those losses. The stock market also suffered a 43.75% decline during the bear market at the start of this decade.

If you don't have the stomach for steep downturns, you might increase your allocation to include more bonds or bond funds. Holding, say, 70% of your portfolio in stocks and 30% in bonds will let you capture most of the long-term growth of stocks while sheltering your investments to a certain extent during market downturns.