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Factorial of 21 is 51090942171709440000 | What is a factorial of 21 ?
How to calculate the factorial of 21
Lets check the detailed answer
21! is exactly: 51090942171709440000
The number of trailing zeros in 21! is 4.
The number of digits in 21 factorial is 20.
The factorial of 21 is 51090942171709440000 calculated, through its definition, this way:
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 1What is factorial of 21?
Definition of factorial of 21
The factorial is a basically a quantity which is defined for integer value 21 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 21 is calculated as 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
Factorial Formula for 21
For 21 is natural number which is greater than or equal to 1. Then we can have the formula as
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 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
Simalar Questions asked in exam for factorial of 21 :-
- Check How many digits are there in 21 factorial?
- What is the factorial of 21?
- How many trailing zeros are in 21 factorial?
- What is the last digits of factorial of 21?
Table for factorial of 1 to 21
| # | 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 |
| 19 | 19 | 121645100408832000 |
| 20 | 20 | 2432902008176640000 |
| 21 | 21 | 51090942171709440000 |
Factorial examples
Example 1:-
What is the factorial of 22?Solution :-
We know that factorial formula for 22 is22! = 22 × (22-1) X (22-2) X (22-3) X (22-4) X (22-5) X (22-6) X (22-7) X (22-8) X (22-9) X (22-10) X (22-11) X (22-12) X (22-13) X (22-14) X (22-15) X (22-16) X (22-17) X (22-18) X (22-19) X (22-20) X (22-21) X (22-22) ..... 22 X 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 22 is
22! = 22 X (22-1) X (22-2) X (22-3) X (22-4) X (22-5) X (22-6) X (22-7) X (22-8) X (22-9) X (22-10) X (22-11) X (22-12) X (22-13) X (22-14) X (22-15) X (22-16) X (22-17) X (22-18) X (22-19) X (22-20) X (22-21) X (22-22)
22! = 22 X 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
22! = 1124000727777607680000
Example 2:-
What is the factorial of 23?Solution :-
We know that factorial formula for 22 is23! = 23 × (23-1) X (23-2) X (23-3) X (23-4) X (23-5) X (23-6) X (23-7) X (23-8) X (23-9) X (23-10) X (23-11) X (23-12) X (23-13) X (23-14) X (23-15) X (23-16) X (23-17) X (23-18) X (23-19) X (23-20) X (23-21) X (23-22) X (23-23) ..... 23 X 22 X 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 23 is
23! = 23 X (23-1) X (23-2) X (23-3) X (23-4) X (23-5) X (23-6) X (23-7) X (23-8) X (23-9) X (23-10) X (23-11) X (23-12) X (23-13) X (23-14) X (23-15) X (23-16) X (23-17) X (23-18) X (23-19) X (23-20) X (23-21) X (23-22) X (23-23)
23! = 23 X 22 X 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
23! = 25852016738884976640000
Example 3:-
What is the factorial of 24?Solution :-
We know that factorial formula for 24 is24! = 24 × (24-1) X (24-2) X (24-3) X (24-4) X (24-5) X (24-6) X (24-7) X (24-8) X (24-9) X (24-10) X (24-11) X (24-12) X (24-13) X (24-14) X (24-15) X (24-16) X (24-17) X (24-18) X (24-19) X (24-20) X (24-21) X (24-22) X (24-23) X (24-24) ..... 24 X 23 X 22 X 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 24 is
24! = 24 X (24-1) X (24-2) X (24-3) X (24-4) X (24-5) X (24-6) X (24-7) X (24-8) X (24-9) X (24-10) X (24-11) X (24-12) X (24-13) X (24-14) X (24-15) X (24-16) X (24-17) X (24-18) X (24-19) X (24-20) X (24-21) X (24-22) X (24-23) X (24-24)
24! = 24 X 23 X 22 X 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
24! = 620448401733239439360000
Frequently Asked Questions(FAQ) for Factorial
What is the factorial of 21?
Click here for detailed step by step calculation for factorial of 21.
Check How many digits are there in 21 factorial?
The number of number of digits in 21 factorial is 20.
What is the meaning of 21 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 20?
The value of factorial of 20 is 2432902008176640000.
What is the factorial of 24?
The value of factorial of 24 is 620448401733239439360000.
What is the factorial of 23?
The value of factorial of 23 is 25852016738884976640000.