Yes, number two economy now. However, the important number is not the aggregate one, but the per capita one. And yes, we should also adjust for PPP, as whjat we really are interested in is living standards and things do cost different amounts in different places (as a trivial example, and iPod costs roughly the same everywhere but a cleaner is much, much, cheaper in a poor country).
And the last time the U.S. had per-capita GDP of $6,567 was back in 1932.
If it hadn\’t been for Mao, how far would China have got do you think? 1950? 1960? 1980 even?