The number 18513
18513 is a composite number with 18 divisors. Its prime factorisation is × × 17. Divisors (18): 1, 3, 9, 11, 17, 33, 51, 99, 121, 153, 187, 363, 561, 1089, 1683, 2057 … 18513.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 18513: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
18513 is composite. Its prime factorisation is
- 3
The divisors add up to 31122; without 18513 itself that is 12609, so 18513 is deficient (12609 is less than 18513). Euler's totient φ(18513) = 10560 numbers up to 18513 share no factor with it.
- 4
The digits of 18513 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 110 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18513 = 3^{2} \times 11^{2} \times 17 \]18513 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 31122 |
| Euler totient φ(n) | 10560 |
| Square | 342731169 |
| Cube | 6344982131697 |
| Square root | 136.062486 (= 33√17) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 110 |
| Scientific notation | 1.8513 × |
18513 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand five hundred and thirteen |
| Binary (base 2) | 100100001010001 |
| Octal (base 8) | 44121 |
| Hexadecimal (base 16) | 4851 |
| Base 3 | 221101200 |
| As time | 18513 seconds = 5 h 8 min 33 s |
Is 18513 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (18513 ÷ 3 = 6171) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | 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 3) | 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 | No (remainder 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (18513 ÷ 9 = 2057) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (18513 ÷ 11 = 1683) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18513 a prime number?
No. 18513 = × × 17, so it is divisible by 3.
What are the factors of 18513?
1, 3, 9, 11, 17, 33, 51, 99, 121, 153, 187, 363, 561, 1089, 1683, 2057, 6171, 18513.
What is 18513 in binary?
100100001010001 (hexadecimal 4851, octal 44121).
What is the square root of 18513?
About 136.0625, exactly 33√17.
Is 18513 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 18513?
18513 is a happy number: repeatedly adding the squares of its digits reaches 1.