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Factorial of 18 is 6402373705728000 | What is a factorial of 18 ?
How to calculate the factorial of 18
Lets check the detailed answer
18! is exactly: 6402373705728000
The number of trailing zeros in 18! is 3.
The number of digits in 18 factorial is 16.
The factorial of 18 is 6402373705728000 calculated, through its definition, this way:
18 X 17 X 16 X 15 X 14 X 13 X 12 X 11 X 10 X 9 X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1What is factorial of 18?
Definition of factorial of 18
The factorial is a basically a quantity which is defined for integer value 18 which is greater than or equal to 0.
The factorial is nothing but the product of all intergers which is less than or equal to n but it is greater than or equal to 1. By definition we can say that the factorial value of 0 is equal to 1. We can not have negative integers factorial as defined. We can see that factorial is the result of multiplying a sequence of descending natural numbers. We can say that factorial of 18 is calculated as 18 X 17 X 16 X 15 X 14 X 13 X 12 X 11 X 10 X 9 X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1
Factorial Formula for 18
For 18 is natural number which is greater than or equal to 1. Then we can have the formula as
18! = 18 x (18-1) X (18-2) X (18-3) X (18-4) X (18-5) X (18-6) X (18-7) X (18-8) X (18-9) X (18-10) X (18-11) X (18-12) X (18-13) X (18-14) X (18-15) X (18-16) X (18-17) X (18-18) ..... 18 X 17 X 16 X 15 X 14 X 13 X 12 X 11 X 10 X 9 X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1
Simalar Questions asked in exam for factorial of 18 :-
- Check How many digits are there in 18 factorial?
- What is the factorial of 18?
- How many trailing zeros are in 18 factorial?
- What is the last digits of factorial of 18?
Table for factorial of 1 to 18
| # | Factorial of | Factorial is |
|---|---|---|
| 1 | 1 | 1 |
| 2 | 2 | 2 |
| 3 | 3 | 6 |
| 4 | 4 | 24 |
| 5 | 5 | 120 |
| 6 | 6 | 720 |
| 7 | 7 | 5040 |
| 8 | 8 | 40320 |
| 9 | 9 | 362880 |
| 10 | 10 | 3628800 |
| 11 | 11 | 39916800 |
| 12 | 12 | 479001600 |
| 13 | 13 | 6227020800 |
| 14 | 14 | 87178291200 |
| 15 | 15 | 1307674368000 |
| 16 | 16 | 20922789888000 |
| 17 | 17 | 355687428096000 |
| 18 | 18 | 6402373705728000 |
Factorial examples
Example 1:-
What is the factorial of 19?Solution :-
We know that factorial formula for 19 is19! = 19 × (19-1) X (19-2) X (19-3) X (19-4) X (19-5) X (19-6) X (19-7) X (19-8) X (19-9) X (19-10) X (19-11) X (19-12) X (19-13) X (19-14) X (19-15) X (19-16) X (19-17) X (19-18) X (19-19) ..... 19 X 18 X 17 X 16 X 15 X 14 X 13 X 12 X 11 X 10 X 9 X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1
So the factorial of 19 is
19! = 19 X (19-1) X (19-2) X (19-3) X (19-4) X (19-5) X (19-6) X (19-7) X (19-8) X (19-9) X (19-10) X (19-11) X (19-12) X (19-13) X (19-14) X (19-15) X (19-16) X (19-17) X (19-18) X (19-19)
19! = 19 X 18 X 17 X 16 X 15 X 14 X 13 X 12 X 11 X 10 X 9 X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1
19! = 121645100408832000
Example 2:-
What is the factorial of 20?Solution :-
We know that factorial formula for 19 is20! = 20 × (20-1) X (20-2) X (20-3) X (20-4) X (20-5) X (20-6) X (20-7) X (20-8) X (20-9) X (20-10) X (20-11) X (20-12) X (20-13) X (20-14) X (20-15) X (20-16) X (20-17) X (20-18) X (20-19) X (20-20) ..... 20 X 19 X 18 X 17 X 16 X 15 X 14 X 13 X 12 X 11 X 10 X 9 X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1
So the factorial of 20 is
20! = 20 X (20-1) X (20-2) X (20-3) X (20-4) X (20-5) X (20-6) X (20-7) X (20-8) X (20-9) X (20-10) X (20-11) X (20-12) X (20-13) X (20-14) X (20-15) X (20-16) X (20-17) X (20-18) X (20-19) X (20-20)
20! = 20 X 19 X 18 X 17 X 16 X 15 X 14 X 13 X 12 X 11 X 10 X 9 X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1
20! = 2432902008176640000
Example 3:-
What is the factorial of 21?Solution :-
We know that factorial formula for 21 is21! = 21 × (21-1) X (21-2) X (21-3) X (21-4) X (21-5) X (21-6) X (21-7) X (21-8) X (21-9) X (21-10) X (21-11) X (21-12) X (21-13) X (21-14) X (21-15) X (21-16) X (21-17) X (21-18) X (21-19) X (21-20) X (21-21) ..... 21 X 20 X 19 X 18 X 17 X 16 X 15 X 14 X 13 X 12 X 11 X 10 X 9 X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1
So the factorial of 21 is
21! = 21 X (21-1) X (21-2) X (21-3) X (21-4) X (21-5) X (21-6) X (21-7) X (21-8) X (21-9) X (21-10) X (21-11) X (21-12) X (21-13) X (21-14) X (21-15) X (21-16) X (21-17) X (21-18) X (21-19) X (21-20) X (21-21)
21! = 21 X 20 X 19 X 18 X 17 X 16 X 15 X 14 X 13 X 12 X 11 X 10 X 9 X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1
21! = 51090942171709440000
Frequently Asked Questions(FAQ) for Factorial
What is the factorial of 18?
Click here for detailed step by step calculation for factorial of 18.
Check How many digits are there in 18 factorial?
The number of number of digits in 18 factorial is 16.
What is the meaning of 18 factorial?
What is the symbol of factorial?
The symbol for factorial is ! (exclamation mark).
What is the factorial of 0?
The value of factorial of 0 is 1, i.e. 0! = 1.
What is the factorial of 17?
The value of factorial of 17 is 355687428096000.
What is the factorial of 21?
The value of factorial of 21 is 51090942171709440000.
What is the factorial of 20?
The value of factorial of 20 is 2432902008176640000.