The US number, as Mish said, ignores at least another $70 trillion in unfunded liabilities / promises that will never be kept.
Japan's debt numbers have only increased over the last 27 years, while its medium cities turned to ghost towns, demographics went from bad to worse (not enough children to even maintain population), and Japan's "leadership" has turned fukashima into a radioactive dump for the next 4000 years.
China's numbers do not include an Enron like dependence on "off balance sheet" financing that isn't really off balance sheet at all. "Social harmony" (aka Tienamen square like rebellion) means all the shadow bank debt is really Bank of China debt. And their UST are worthless since Uncle Sam cannot (is not able to) keep promises to US voters never mind foreigners.
Italy's numbers are not believable either. The Italian people don't trust Rome and consider tax evasion as their national sport.
And France, when their comical military isn't surrendering, is so anti-business its a wonder anyone was actually dumb enough to lend to them.
It won't get better until the whole G7 admits that Keynesian policy is just plain stupid at its very core.