The number 18018
18018 is a composite number with 48 divisors. Its prime factorisation is 2 × × 7 × 11 × 13. Divisors (48): 1, 2, 3, 6, 7, 9, 11, 13, 14, 18, 21, 22, 26, 33, 39, 42 … 18018.
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How to work it out
- 1
What is special about 18018: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
18018 is composite. Its prime factorisation is
- 3
The divisors add up to 52416; without 18018 itself that is 34398, so 18018 is abundant (34398 is more than 18018). Euler's totient φ(18018) = 4320 numbers up to 18018 share no factor with it.
- 4
The digits of 18018 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 40 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18018 = 2 \times 3^{2} \times 7 \times 11 \times 13 \]18018 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 52416 |
| Euler totient φ(n) | 4320 |
| Square | 324648324 |
| Cube | 5849513501832 |
| Square root | 134.231144 (= 3√2002) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 40 |
| Scientific notation | 1.8018 × |
18018 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand and eighteen |
| Binary (base 2) | 100011001100010 |
| Octal (base 8) | 43142 |
| Hexadecimal (base 16) | 4662 |
| Base 3 | 220201100 |
| As time | 18018 seconds = 5 h 0 min 18 s |
Is 18018 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18018 ÷ 2 = 9009) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (18018 ÷ 3 = 6006) | 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 | Yes (18018 ÷ 6 = 3003) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (18018 ÷ 7 = 2574) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (18018 ÷ 9 = 2002) | 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 | Yes (18018 ÷ 11 = 1638) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18018 a prime number?
No. 18018 = 2 × × 7 × 11 × 13, so it is divisible by 2.
What are the factors of 18018?
1, 2, 3, 6, 7, 9, 11, 13, 14, 18, 21, 22, 26, 33, 39, 42, 63, 66, 77, 78, 91, 99, 117, 126, 143, 154, 182, 198, 231, 234, 273, 286, 429, 462, 546, 693, 819, 858, 1001, 1287, 1386, 1638, 2002, 2574, 3003, 6006, 9009, 18018.
What is 18018 in binary?
100011001100010 (hexadecimal 4662, octal 43142).
What is the square root of 18018?
About 134.2311, exactly 3√2002.
Is 18018 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 18018?
18018 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.