The number 18998
18998 is a composite number with 16 divisors. Its prime factorisation is 2 × 7 × 23 × 59. Divisors (16): 1, 2, 7, 14, 23, 46, 59, 118, 161, 322, 413, 826, 1357, 2714, 9499, 18998.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18998: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
18998 is composite. Its prime factorisation is
- 3
The divisors add up to 34560; without 18998 itself that is 15562, so 18998 is deficient (15562 is less than 18998). Euler's totient φ(18998) = 7656 numbers up to 18998 share no factor with it.
- 4
The digits of 18998 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 105 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18998 = 2 \times 7 \times 23 \times 59 \]
18998 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 34560 |
| Euler totient φ(n) | 7656 |
| Square | 360924004 |
| Cube | 6856834227992 |
| Square root | 137.833233 |
| Digit sum / digital root | 35 / 8 |
| Collatz steps to 1 | 105 |
| Scientific notation | 1.8998 × |
18998 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand nine hundred and ninety-eight |
| Binary (base 2) | 100101000110110 |
| Octal (base 8) | 45066 |
| Hexadecimal (base 16) | 4A36 |
| Base 3 | 222001122 |
| As time | 18998 seconds = 5 h 16 min 38 s |
Is 18998 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18998 ÷ 2 = 9499) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (18998 ÷ 7 = 2714) | 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 6) | 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 8) | 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 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18998 a prime number?
No. 18998 = 2 × 7 × 23 × 59, so it is divisible by 2.
What are the factors of 18998?
1, 2, 7, 14, 23, 46, 59, 118, 161, 322, 413, 826, 1357, 2714, 9499, 18998.
What is 18998 in binary?
100101000110110 (hexadecimal 4A36, octal 45066).
What is the square root of 18998?
About 137.8332.
Is 18998 divisible by 3?
No. Its digits add up to 35, which is not a multiple of 3.
What is special about the number 18998?
18998 is a happy number: repeatedly adding the squares of its digits reaches 1.