The number 31289
31289 is a composite number with 4 divisors. Its prime factorisation is 67 × 467. Divisors (4): 1, 67, 467, 31289.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31289: a semiprime: 67 × 467, the product of two primes.
- 2
31289 is composite. Its prime factorisation is
- 3
The divisors add up to 31824; without 31289 itself that is 535, so 31289 is deficient (535 is less than 31289). Euler's totient φ(31289) = 30756 numbers up to 31289 share no factor with it.
- 4
The digits of 31289 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 147 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31289 = 67 \times 467 \]
31289 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 31824 |
| Euler totient φ(n) | 30756 |
| Square | 979001521 |
| Cube | 30631978590569 |
| Square root | 176.886970 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 147 |
| Scientific notation | 3.1289 × |
31289 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand two hundred and eighty-nine |
| Binary (base 2) | 111101000111001 |
| Octal (base 8) | 75071 |
| Hexadecimal (base 16) | 7A39 |
| Base 3 | 1120220212 |
| As time | 31289 seconds = 8 h 41 min 29 s |
Is 31289 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 1) | 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 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31289 a prime number?
No. 31289 = 67 × 467, so it is divisible by 67.
What are the factors of 31289?
1, 67, 467, 31289.
What is 31289 in binary?
111101000111001 (hexadecimal 7A39, octal 75071).
What is the square root of 31289?
About 176.8870.
Is 31289 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 31289?
31289 is a semiprime: 67 × 467, the product of two primes.