The number 18810
18810 is a composite number with 48 divisors. Its prime factorisation is 2 × × 5 × 11 × 19. Divisors (48): 1, 2, 3, 5, 6, 9, 10, 11, 15, 18, 19, 22, 30, 33, 38, 45 … 18810.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18810: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
18810 is composite. Its prime factorisation is
- 3
The divisors add up to 56160; without 18810 itself that is 37350, so 18810 is abundant (37350 is more than 18810). Euler's totient φ(18810) = 4320 numbers up to 18810 share no factor with it.
- 4
The digits of 18810 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 61 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18810 = 2 \times 3^{2} \times 5 \times 11 \times 19 \]18810 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 56160 |
| Euler totient φ(n) | 4320 |
| Square | 353816100 |
| Cube | 6655280841000 |
| Square root | 137.149553 (= 3√2090) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 61 |
| Scientific notation | 1.881 × |
18810 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand eight hundred and ten |
| Binary (base 2) | 100100101111010 |
| Octal (base 8) | 44572 |
| Hexadecimal (base 16) | 497A |
| Base 3 | 221210200 |
| As time | 18810 seconds = 5 h 13 min 30 s |
Is 18810 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18810 ÷ 2 = 9405) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (18810 ÷ 3 = 6270) | 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 | Yes (18810 ÷ 5 = 3762) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (18810 ÷ 6 = 3135) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 (18810 ÷ 9 = 2090) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (18810 ÷ 10 = 1881) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (18810 ÷ 11 = 1710) | 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 18810 a prime number?
No. 18810 = 2 × × 5 × 11 × 19, so it is divisible by 2.
What are the factors of 18810?
1, 2, 3, 5, 6, 9, 10, 11, 15, 18, 19, 22, 30, 33, 38, 45, 55, 57, 66, 90, 95, 99, 110, 114, 165, 171, 190, 198, 209, 285, 330, 342, 418, 495, 570, 627, 855, 990, 1045, 1254, 1710, 1881, 2090, 3135, 3762, 6270, 9405, 18810.
What is 18810 in binary?
100100101111010 (hexadecimal 497A, octal 44572).
What is the square root of 18810?
About 137.1496, exactly 3√2090.
Is 18810 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 18810?
18810 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.