I do.
The answer to your question is no, the United States currently is not the richest nation on the Earth.
That distinction belongs to Luxembourg, which has a Gross National Product of $36,400 U.S. dollars, according to www.aneki.com
The United States is in second place, with a Gross National Product of $36,200 U.S. dollars.
I'm searching through the World Banks online records right now, trying to verify this.