While Gross Domestic Product (GDP) is the favoured method of measuring a nation's wealth, it is open to criticism on a number of fronts. Nonetheless, it is a most useful arbiter. One notes that per capita GDP is a more accurate indicator with differencebetween.org noting that Luxembourg though possessing a relatively meagre GDP is better off than India with its higher figure being shared among a much higher population.
In terms of risking economic theory, it would do to remember that there are a range of results, with wikipedia quoting 2014 figures putting the US ahead of China. Depending on whether your narrative concerns Chinese ownership of Australian land and industry or fear of a Trump presidency, might determine which way you proceed.
Just as not all Chinese nationals get to share (equally) in that nineteen and a half trillion, neither should we assume that every Qatar national is actually the recipient of a hundred and thirty three grand a year.
Mount a Marxist attack on wealth distribution in the United States and you get hit with the information that their per capita take is just outside the top ten. France also sits well in both criteria.