The number 23989
23989 is a composite number with 8 divisors. Its prime factorisation is 7 × 23 × 149. Divisors (8): 1, 7, 23, 149, 161, 1043, 3427, 23989.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 23989: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
23989 is composite. Its prime factorisation is
- 3
The divisors add up to 28800; without 23989 itself that is 4811, so 23989 is deficient (4811 is less than 23989). Euler's totient φ(23989) = 19536 numbers up to 23989 share no factor with it.
- 4
The digits of 23989 add up to 31, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 51 steps to reach 1.
LaTeX source of the formulas on this page
\[ 23989 = 7 \times 23 \times 149 \]
23989 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 28800 |
| Euler totient φ(n) | 19536 |
| Square | 575472121 |
| Cube | 13805000710669 |
| Square root | 154.883827 |
| Digit sum / digital root | 31 / 4 |
| Collatz steps to 1 | 51 |
| Scientific notation | 2.3989 × |
23989 in other forms
| Form | Value |
|---|---|
| In words | twenty-three thousand nine hundred and eighty-nine |
| Binary (base 2) | 101110110110101 |
| Octal (base 8) | 56665 |
| Hexadecimal (base 16) | 5DB5 |
| Base 3 | 1012220111 |
| As time | 23989 seconds = 6 h 39 min 49 s |
Is 23989 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 | Yes (23989 ÷ 7 = 3427) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | 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 9) | 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 23989 a prime number?
No. 23989 = 7 × 23 × 149, so it is divisible by 7.
What are the factors of 23989?
1, 7, 23, 149, 161, 1043, 3427, 23989.
What is 23989 in binary?
101110110110101 (hexadecimal 5DB5, octal 56665).
What is the square root of 23989?
About 154.8838.
Is 23989 divisible by 3?
No. Its digits add up to 31, which is not a multiple of 3.
What is special about the number 23989?
23989 is a happy number: repeatedly adding the squares of its digits reaches 1.