The number 12431
12431 is a composite number with 4 divisors. Its prime factorisation is 31 × 401. Divisors (4): 1, 31, 401, 12431.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 12431: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 31 × 401, the product of two primes.
- 2
12431 is composite. Its prime factorisation is
- 3
The divisors add up to 12864; without 12431 itself that is 433, so 12431 is deficient (433 is less than 12431). Euler's totient φ(12431) = 12000 numbers up to 12431 share no factor with it.
- 4
The digits of 12431 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 63 steps to reach 1.
LaTeX source of the formulas on this page
\[ 12431 = 31 \times 401 \]
12431 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 12864 |
| Euler totient φ(n) | 12000 |
| Square | 154529761 |
| Cube | 1920959458991 |
| Square root | 111.494394 |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 63 |
| Scientific notation | 1.2431 × |
12431 in other forms
| Form | Value |
|---|---|
| In words | twelve thousand four hundred and thirty-one |
| Binary (base 2) | 11000010001111 |
| Octal (base 8) | 30217 |
| Hexadecimal (base 16) | 308F |
| Base 3 | 122001102 |
| As time | 12431 seconds = 3 h 27 min 11 s |
Is 12431 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 6) | 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 2) | 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 1) | 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 12431 a prime number?
No. 12431 = 31 × 401, so it is divisible by 31.
What are the factors of 12431?
1, 31, 401, 12431.
What is 12431 in binary?
11000010001111 (hexadecimal 308F, octal 30217).
What is the square root of 12431?
About 111.4944.
Is 12431 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 12431?
12431 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 31 × 401, the product of two primes.