Keystroke: !
n!
Returns n(n-1)(n-2)...1.
Operands:
- n is a nonnegative integer.
Notes:
- Factorials for n > 170 overflow when evaluated
numerically, but can be evaluated by the symbolic
processor.
- For fractional factorials, use the gamma
function using this relationship:
Γ(n+1) = n!