The number 20431
20431 is the 2308th prime number. Its only divisors are 1 and 20431.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20431: the 2308th prime number.
- 2
20431 is prime, so its only factors are 1 and 20431. It is the 2308th prime; the next prime is 20441 and the one before is 20411.
- 3
The divisors add up to 20432; without 20431 itself that is 1, so 20431 is deficient (1 is less than 20431). Euler's totient φ(20431) = 20430 numbers up to 20431 share no factor with it.
- 4
The digits of 20431 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 149 steps to reach 1.
20431 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 20432 |
| Euler totient φ(n) | 20430 |
| Square | 417425761 |
| Cube | 8528425722991 |
| Square root | 142.937049 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 149 |
| Scientific notation | 2.0431 × |
20431 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand four hundred and thirty-one |
| Binary (base 2) | 100111111001111 |
| Octal (base 8) | 47717 |
| Hexadecimal (base 16) | 4FCF |
| Base 3 | 1001000201 |
| As time | 20431 seconds = 5 h 40 min 31 s |
Is 20431 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20431 a prime number?
Yes. 20431 is divisible only by 1 and itself.
What are the factors of 20431?
1, 20431.
What is 20431 in binary?
100111111001111 (hexadecimal 4FCF, octal 47717).
What is the square root of 20431?
About 142.9370.
Is 20431 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 20431?
20431 is the 2308th prime number.