The number 18520
18520 is a composite number with 16 divisors. Its prime factorisation is × 5 × 463. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 463, 926, 1852, 2315, 3704, 4630, 9260, 18520.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18520: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
18520 is composite. Its prime factorisation is
- 3
The divisors add up to 41760; without 18520 itself that is 23240, so 18520 is abundant (23240 is more than 18520). Euler's totient φ(18520) = 7392 numbers up to 18520 share no factor with it.
- 4
The digits of 18520 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 110 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18520 = 2^{3} \times 5 \times 463 \]18520 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 41760 |
| Euler totient φ(n) | 7392 |
| Square | 342990400 |
| Cube | 6352182208000 |
| Square root | 136.088207 (= 2√4630) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 110 |
| Scientific notation | 1.852 × |
18520 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand five hundred and twenty |
| Binary (base 2) | 100100001011000 |
| Octal (base 8) | 44130 |
| Hexadecimal (base 16) | 4858 |
| Base 3 | 221101221 |
| As time | 18520 seconds = 5 h 8 min 40 s |
Is 18520 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18520 ÷ 2 = 9260) | 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 | Yes (18520 ÷ 4 = 4630) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (18520 ÷ 5 = 3704) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | 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 | Yes (18520 ÷ 8 = 2315) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (18520 ÷ 10 = 1852) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18520 a prime number?
No. 18520 = × 5 × 463, so it is divisible by 2.
What are the factors of 18520?
1, 2, 4, 5, 8, 10, 20, 40, 463, 926, 1852, 2315, 3704, 4630, 9260, 18520.
What is 18520 in binary?
100100001011000 (hexadecimal 4858, octal 44130).
What is the square root of 18520?
About 136.0882, exactly 2√4630.
Is 18520 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 18520?
18520 is a happy number: repeatedly adding the squares of its digits reaches 1.