# Manuals/calci/FACTORIAL

**FACTORIAL (Number)**

- is any positive integer.

## Description

- This function is showing the result of factorial of a number.
- Factorial means the result of multiplying a sequence of descending natural numbers down to 1.
- In , is any positive integer.
- So the factorial is defined for a positive integer n as:

.

- For example 4!=4*3*2*1 = 24.
- The given number will truncated to integer if the given number is in Decimal.
- This function will returns the result as NaN when the given number is in negative.

## Examples

- FACTORIAL(9) = 362880
- FACTORIAL(4.3) = 38.0779764499523
- FACTORIAL(54) = 2.308436973392414e+71
- FACTORIAL(-3) = Infinity
- a=(5!)! = 6.689502913449128e+198

## Related Videos

## See Also

## References