The U.S. debt was more than $14.3 trillion during the so-called debt crisis of 2011, when the level of borrowing reached its statutory limit and the president warned of a potential default if the cap wasn't raised.
See also: 5 Presidents Who Raised the Debt Ceiling
So who owns all that U.S. debt?
About 32 cents for every dollar of U.S. debt, or $4.6 trillion, is owned by the federal government in trust funds, for Social Security and other programs such as retirement accounts, according to the U.S. Department of Treasury.
China and U.S. Debt
The largest portion of U.S. debt, 68 cents for every dollar or about $10 trillion, is owned by individual investors, corporations, state and local governments and, yes, even foreign governments such as China that hold Treasury bills, notes and bonds.
Foreign governments hold about 46 percent of all U.S. debt held by the public, more than $4.5 trillion. The largest foreign holder of U.S. debt is China, which owns more about $1.2 trillion in bills, notes and bonds, according to the Treasury.
In total, China owns about 8 percent of publicly held U.S. debt. Of all the holders of U.S. debt China is the third-largest, behind only the Social Security Trust Fund's holdings of nearly $3 trillion and the Federal Reserve's nearly $2 trillion holdings in Treasury investments, purchased as part of its quantitative easing program to boost the economy.
Criticism of China Owning U.S. Debt
To put China's ownership of U.S. debt in perspective, its holding of $1.2 trillion is even larger than the amount owned by American households. U.S. citizens hold only about $959 billion in U.S. debt, according to the Federal Reserve.
Other large foreign holders of U.S. debt include Japan, which owns $912 billion; the United Kingdom, which owns $347 billion; Brazil, which holds $211 billion; Taiwan, which holds $153 billion; and Hong Kong, which owns $122 billion.
See also: Debt Ceiling History
Some Republicans have expressed concern over the amount of U.S. debt owned by China. Republican U.S. Rep. Michele Bachmann, a 2012 presidential hopeful, joked that when it came to the debt "Hu's your daddy," a reference to Chinese President Hu Jintao.
Despite such joking, the truth is the bulk of the $14.3 trillion U.S. debt - $9.8 trillion in all - is owned by the American people and its government.
That's the good news.
The bad news?
That's still a lot of IOUs.