The number 18920
18920 is a composite number with 32 divisors. Its prime factorisation is × 5 × 11 × 43. Divisors (32): 1, 2, 4, 5, 8, 10, 11, 20, 22, 40, 43, 44, 55, 86, 88, 110 … 18920.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18920: a Harshad number: divisible by its digit sum 20.
- 2
18920 is composite. Its prime factorisation is
- 3
The divisors add up to 47520; without 18920 itself that is 28600, so 18920 is abundant (28600 is more than 18920). Euler's totient φ(18920) = 6720 numbers up to 18920 share no factor with it.
- 4
The digits of 18920 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 61 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18920 = 2^{3} \times 5 \times 11 \times 43 \]18920 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 47520 |
| Euler totient φ(n) | 6720 |
| Square | 357966400 |
| Cube | 6772724288000 |
| Square root | 137.549991 (= 2√4730) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 61 |
| Scientific notation | 1.892 × |
18920 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand nine hundred and twenty |
| Binary (base 2) | 100100111101000 |
| Octal (base 8) | 44750 |
| Hexadecimal (base 16) | 49E8 |
| Base 3 | 221221202 |
| As time | 18920 seconds = 5 h 15 min 20 s |
Is 18920 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18920 ÷ 2 = 9460) | 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 | Yes (18920 ÷ 4 = 4730) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (18920 ÷ 5 = 3784) | 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 | No (remainder 6) | 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 (18920 ÷ 8 = 2365) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (18920 ÷ 10 = 1892) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (18920 ÷ 11 = 1720) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18920 a prime number?
No. 18920 = × 5 × 11 × 43, so it is divisible by 2.
What are the factors of 18920?
1, 2, 4, 5, 8, 10, 11, 20, 22, 40, 43, 44, 55, 86, 88, 110, 172, 215, 220, 344, 430, 440, 473, 860, 946, 1720, 1892, 2365, 3784, 4730, 9460, 18920.
What is 18920 in binary?
100100111101000 (hexadecimal 49E8, octal 44750).
What is the square root of 18920?
About 137.5500, exactly 2√4730.
Is 18920 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 18920?
18920 is a Harshad number: divisible by its digit sum 20.