The number 431
431 is a twin prime (431 and 433 are both prime) and the 83rd prime number. Its only divisors are 1 and 431.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 431: a twin prime (431 and 433 are both prime); the 83rd prime number.
- 2
431 is prime, so its only factors are 1 and 431. It is the 83rd prime; the next prime is 433 and the one before is 421.
- 3
The divisors add up to 432; without 431 itself that is 1, so 431 is deficient (1 is less than 431). Euler's totient φ(431) = 430 numbers up to 431 share no factor with it.
- 4
The digits of 431 add up to 8, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 40 steps to reach 1.
431 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 432 |
| Euler totient φ(n) | 430 |
| Square | 185761 |
| Cube | 80062991 |
| Square root | 20.760539 |
| Digit sum / digital root | 8 / 8 |
| Collatz steps to 1 | 40 |
| Scientific notation | 4.31 × |
431 in other forms
| Form | Value |
|---|---|
| In words | four hundred and thirty-one |
| Roman numerals | CDXXXI |
| Binary (base 2) | 110101111 |
| Octal (base 8) | 657 |
| Hexadecimal (base 16) | 1AF |
| Base 3 | 120222 |
| As time | 431 seconds = 7 min 11 s |
Is 431 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 2) | 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 8) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 431 a prime number?
Yes. 431 is divisible only by 1 and itself.
What are the factors of 431?
1, 431.
What is 431 in binary?
110101111 (hexadecimal 1AF, octal 657).
What is the square root of 431?
About 20.7605.
What is 431 in Roman numerals?
CDXXXI.
Is 431 divisible by 3?
No. Its digits add up to 8, which is not a multiple of 3.
What is special about the number 431?
431 is a twin prime (431 and 433 are both prime); the 83rd prime number.