The number 21267
21267 is a composite number with 12 divisors. Its prime factorisation is × 17 × 139. Divisors (12): 1, 3, 9, 17, 51, 139, 153, 417, 1251, 2363, 7089, 21267.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21267: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
21267 is composite. Its prime factorisation is
- 3
The divisors add up to 32760; without 21267 itself that is 11493, so 21267 is deficient (11493 is less than 21267). Euler's totient φ(21267) = 13248 numbers up to 21267 share no factor with it.
- 4
The digits of 21267 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 149 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21267 = 3^{2} \times 17 \times 139 \]21267 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 32760 |
| Euler totient φ(n) | 13248 |
| Square | 452285289 |
| Cube | 9618751241163 |
| Square root | 145.832095 (= 3√2363) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 149 |
| Scientific notation | 2.1267 × |
21267 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand two hundred and sixty-seven |
| Binary (base 2) | 101001100010011 |
| Octal (base 8) | 51423 |
| Hexadecimal (base 16) | 5313 |
| Base 3 | 1002011200 |
| As time | 21267 seconds = 5 h 54 min 27 s |
Is 21267 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 (21267 ÷ 3 = 7089) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | 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 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (21267 ÷ 9 = 2363) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21267 a prime number?
No. 21267 = × 17 × 139, so it is divisible by 3.
What are the factors of 21267?
1, 3, 9, 17, 51, 139, 153, 417, 1251, 2363, 7089, 21267.
What is 21267 in binary?
101001100010011 (hexadecimal 5313, octal 51423).
What is the square root of 21267?
About 145.8321, exactly 3√2363.
Is 21267 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 21267?
21267 is a happy number: repeatedly adding the squares of its digits reaches 1.