The number 18989
18989 is a composite number with 4 divisors. Its prime factorisation is 17 × 1117. Divisors (4): 1, 17, 1117, 18989.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18989: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 17 × 1117, the product of two primes.
- 2
18989 is composite. Its prime factorisation is
- 3
The divisors add up to 20124; without 18989 itself that is 1135, so 18989 is deficient (1135 is less than 18989). Euler's totient φ(18989) = 17856 numbers up to 18989 share no factor with it.
- 4
The digits of 18989 add up to 35, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 154 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18989 = 17 \times 1117 \]
18989 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 20124 |
| Euler totient φ(n) | 17856 |
| Square | 360582121 |
| Cube | 6847093895669 |
| Square root | 137.800581 |
| Digit sum / digital root | 35 / 8 |
| Collatz steps to 1 | 154 |
| Scientific notation | 1.8989 × |
18989 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand nine hundred and eighty-nine |
| Binary (base 2) | 100101000101101 |
| Octal (base 8) | 45055 |
| Hexadecimal (base 16) | 4A2D |
| Base 3 | 222001022 |
| As time | 18989 seconds = 5 h 16 min 29 s |
Is 18989 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 5) | 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 8) | 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 3) | 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 18989 a prime number?
No. 18989 = 17 × 1117, so it is divisible by 17.
What are the factors of 18989?
1, 17, 1117, 18989.
What is 18989 in binary?
100101000101101 (hexadecimal 4A2D, octal 45055).
What is the square root of 18989?
About 137.8006.
Is 18989 divisible by 3?
No. Its digits add up to 35, which is not a multiple of 3.
What is special about the number 18989?
18989 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 17 × 1117, the product of two primes.