My main source here is the Wikipedia page for world distribution of wealth. We'll use figures based on actual currency exchange rates, not PPP.
The average net worth is $20,372, so we need to divide all the figures by 291 to convert to life expectancy.
So, average life expectancy in the Democratic Republic of Congo would be 7½ months. Average life expectancy in Japan would be 621 years. In the UK, it would be 436 years. Carlos Slim would live to be over 250 million years old, and could watch the continents move around and whole new classes and genera of live evolving. 3 billion people would live less than 34 years, including of course a very large number who would die at birth.
It's really up to you whether you take this as good news that life expectancy is not distributed as unequally as wealth, or bad news that wealth isn't distributed as evenly as life expectancy.