The number 31489
31489 is the 3389th prime number. Its only divisors are 1 and 31489.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31489: the 3389th prime number.
- 2
31489 is prime, so its only factors are 1 and 31489. It is the 3389th prime; the next prime is 31511 and the one before is 31481.
- 3
The divisors add up to 31490; without 31489 itself that is 1, so 31489 is deficient (1 is less than 31489). Euler's totient φ(31489) = 31488 numbers up to 31489 share no factor with it.
- 4
The digits of 31489 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 116 steps to reach 1.
31489 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 31490 |
| Euler totient φ(n) | 31488 |
| Square | 991557121 |
| Cube | 31223142183169 |
| Square root | 177.451402 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 116 |
| Scientific notation | 3.1489 × |
31489 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand four hundred and eighty-nine |
| Binary (base 2) | 111101100000001 |
| Octal (base 8) | 75401 |
| Hexadecimal (base 16) | 7B01 |
| Base 3 | 1121012021 |
| As time | 31489 seconds = 8 h 44 min 49 s |
Is 31489 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 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 7) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31489 a prime number?
Yes. 31489 is divisible only by 1 and itself.
What are the factors of 31489?
1, 31489.
What is 31489 in binary?
111101100000001 (hexadecimal 7B01, octal 75401).
What is the square root of 31489?
About 177.4514.
Is 31489 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 31489?
31489 is the 3389th prime number.