The United States has more billionaires than any other country, according to the Wealth-X and UBS Billionaire Census 2013.

A total of 515 billionaires resided in the United States as of last year, with average wealth of $4.2 billion each. The 515 billionaires represented 24 percent of the world's total of 2,170.

The number of U.S. billionaires rose 7.3 percent from 480 in 2012, and the average wealth of U.S. billionaires dipped in 2013 from $4.3 billion a year earlier.

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China placed second, with 157 billionaires, who were each worth $2.4 billion on average. The number of billionaires was up 6.8 percent from 147 in 2012. And the average wealth total was down from $2.6 billion in 2012.

Germany took third place with 148 billionaires who were each worth $2.9 billion on average. It was followed by the United Kingdom with 135 billionaires worth $3.1 billion each on average, and Russia with 108 billionaires worth $3.2 billion each on average.

Meanwhile, CNNMoney has put together a list of the highest-income zip codes, using median adjusted gross income from 2011.

Fisher Island, Fla. (zip code 33109), which is located next to Miami, tops the list with a median income of $1.08 million.

Atherton, Cal. (94027), which sits in the heart of Silicon Valley, places second with a median income of $1.06 million.

New Vernon, N.J. (07976), which is about 18 miles west of Newark, takes third with a median income of $678,777.

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