The number 31439
31439 is a composite number with 4 divisors. Its prime factorisation is 149 × 211. Divisors (4): 1, 149, 211, 31439.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31439: a semiprime: 149 × 211, the product of two primes.
- 2
31439 is composite. Its prime factorisation is
- 3
The divisors add up to 31800; without 31439 itself that is 361, so 31439 is deficient (361 is less than 31439). Euler's totient φ(31439) = 31080 numbers up to 31439 share no factor with it.
- 4
The digits of 31439 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 129 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31439 = 149 \times 211 \]
31439 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 31800 |
| Euler totient φ(n) | 31080 |
| Square | 988410721 |
| Cube | 31074644657519 |
| Square root | 177.310462 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 129 |
| Scientific notation | 3.1439 × |
31439 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand four hundred and thirty-nine |
| Binary (base 2) | 111101011001111 |
| Octal (base 8) | 75317 |
| Hexadecimal (base 16) | 7ACF |
| Base 3 | 1121010102 |
| As time | 31439 seconds = 8 h 43 min 59 s |
Is 31439 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 4) | 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 2) | 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 9) | 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 31439 a prime number?
No. 31439 = 149 × 211, so it is divisible by 149.
What are the factors of 31439?
1, 149, 211, 31439.
What is 31439 in binary?
111101011001111 (hexadecimal 7ACF, octal 75317).
What is the square root of 31439?
About 177.3105.
Is 31439 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 31439?
31439 is a semiprime: 149 × 211, the product of two primes.