WordNum(n1 [, n2 [, k ]])
n1 is not a number.
The integral value of n1 is negative.
The integral value of n1 is greater than 922,337,203,685,477,550.
n2 (Optional)
If you do not include a value for n2, the function uses the default value (0).
k (Optional)
This example uses the first occurrence of Amount as the conversion number.

WordNum