Order! Order! Puzzle

The story is told of the enterprising young farmer who crossed a sheep with a frog. Before long he had a sign outside the farm: "Woolly Jumpers For Sale". I digress. Let's have some order round here!

Write out the numbers from 1 to 20 in words:

One, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty.

Now put them in ALPHABETICAL order. Which number stays where it is?