www.treasurydirect.gov puts the debt at around $17.3 trillion (this will change, so I'm not putting an exact amount).
A related quote from Wikipedia
On December 12, 2013, debt held by the public was approximately $12.312 trillion or about 73% of Q3 2013 GDP[5][6] Intragovernmental holdings stood at $4.9 trillion (29%), giving a combined total public debt of $17.226 trillion or over 100% GDP
Now, the reason I'm doubting this is because of two "dissenters". One says it is $90 trillion UC PROFESSOR PEGS NATIONAL DEBT AT NEARLY $90 TRILLION DOLLARS; and one says the US has a surplus of $1,138.26 trillion
Are either of those correct? The original article that piqued my interest was in Barrons entitled No Accounting for Government Cost.
Here's how the article starts:
The financial position of the U.S. is not just troubled; it is artificially created to fool the people.
A quote from the article that makes the claim is:
The government's financial reporting is misleading because our political leaders have subverted the democratic process to advance their personal interests. They have spent enormous sums of taxed and borrowed money to endear themselves to the electorate, but they do not want to be held accountable for the full extent of this spending. Hence, the legislative and executive branches collude to underreport expenditures.
In reality, the federal government's existing legal obligations exceed $90 trillion, which is far above the carefully defined debt-ceiling limit of $16.7 trillion and is almost six times the size of the gross domestic product.
A few paragraphs later:
The Constitution's statement and account clause requires that "a regular Statement and Account of the Receipts and Expenditures of all public Money shall be published from time to time." Congress' false reporting has resulted in the violation of several rights, including the right to vote, freedom of speech, due process, equal protection, the right to financial information, and the right to political accountability.
So he is directly claiming that Congress is falsifying data. If you can't view that article, Google No Accounting for Government Cost and select the Barron's article to view the whole article. For some reason the direct link only gives an excerpt.