Factorial Calculator
n factorial, the number of digits it has and the value of (n−1)!.
Results
Result
3,628,800
Number
7
Result
362,880
What this tool does
Factorials grow faster than almost anything else in mathematics: 10! is under four million, but 20! passes two billion billion. The digit count is shown because beyond about 21! the number stops fitting in ordinary computer arithmetic and only the leading digits stay exact.
Formula
n! = n × (n−1) × … × 2 × 1
Variables
| Symbol | Meaning | Unit |
|---|---|---|
n | Number | — |
F | Result | — |
D | Number | — |
P | Result | — |
Worked example
- Number10
- Result3,628,800
- Number7
- Result362,880
Limitations
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.