According to the above link, the US mean family net worth in 2001 was $395,500. This number factors in financial assets (CDs, stock, cash, etc.), non-financial assets (cars, houses, etc.), and personal debt (mortgages, credit cards, etc.). (btw, a very interesting link, Freddy)
A cursory skimming of the article didn’t tell me how big the average “family” was, but it did mention that “family” was roughly equivalent to a census “household” – ie includes single people, couples, and people with children. My swag for a typical “family” (ie “houeshold”) is between 2 and 3 people. So that means that mean net worth (~“wealth”) per person in 2001 was probably somewhere between $133,000 and $200,000. I feel poor now.
GDP is irrelevant to the OP’s question. The OP asked if we divided up all of the wealth not all of the income. It is possible to have lots of one and little of the other (or lots of both… or none of either.)