The number 21060
21060 is a composite number with 60 divisors. Its prime factorisation is × × 5 × 13. Divisors (60): 1, 2, 3, 4, 5, 6, 9, 10, 12, 13, 15, 18, 20, 26, 27, 30 … 21060.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21060: a Harshad number: divisible by its digit sum 9.
- 2
21060 is composite. Its prime factorisation is
- 3
The divisors add up to 71148; without 21060 itself that is 50088, so 21060 is abundant (50088 is more than 21060). Euler's totient φ(21060) = 5184 numbers up to 21060 share no factor with it.
- 4
The digits of 21060 add up to 9, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 43 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21060 = 2^{2} \times 3^{4} \times 5 \times 13 \]21060 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 60 |
| Sum of divisors | 71148 |
| Euler totient φ(n) | 5184 |
| Square | 443523600 |
| Cube | 9340607016000 |
| Square root | 145.120639 (= 18√65) |
| Digit sum / digital root | 9 / 9 |
| Collatz steps to 1 | 43 |
| Scientific notation | 2.106 × |
21060 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand and sixty |
| Binary (base 2) | 101001001000100 |
| Octal (base 8) | 51104 |
| Hexadecimal (base 16) | 5244 |
| Base 3 | 1001220000 |
| As time | 21060 seconds = 5 h 51 min 0 s |
Is 21060 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21060 ÷ 2 = 10530) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21060 ÷ 3 = 7020) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (21060 ÷ 4 = 5265) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (21060 ÷ 5 = 4212) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (21060 ÷ 6 = 3510) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (21060 ÷ 9 = 2340) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (21060 ÷ 10 = 2106) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (21060 ÷ 12 = 1755) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21060 a prime number?
No. 21060 = × × 5 × 13, so it is divisible by 2.
What are the factors of 21060?
1, 2, 3, 4, 5, 6, 9, 10, 12, 13, 15, 18, 20, 26, 27, 30, 36, 39, 45, 52, 54, 60, 65, 78, 81, 90, 108, 117, 130, 135, 156, 162, 180, 195, 234, 260, 270, 324, 351, 390, 405, 468, 540, 585, 702, 780, 810, 1053, 1170, 1404, 1620, 1755, 2106, 2340, 3510, 4212, 5265, 7020, 10530, 21060.
What is 21060 in binary?
101001001000100 (hexadecimal 5244, octal 51104).
What is the square root of 21060?
About 145.1206, exactly 18√65.
Is 21060 divisible by 3?
Yes. Its digits add up to 9, a multiple of 3.
What is special about the number 21060?
21060 is a Harshad number: divisible by its digit sum 9.