Youngest
Billionaire
 
Screen 1 of 2
Kylie Jenner
has
become
 
the
youngest
 
self-made
billionaire
ever,
at
 
the
age
 
of
21.
The reality
TV
star
overtook
Facebook
tycoon
 
Mark Zuckerberg
 
to
top
 
Forbes'
annual
billionaires
list.