The number 21834
21834 is a composite number with 12 divisors. Its prime factorisation is 2 × × 1213. Divisors (12): 1, 2, 3, 6, 9, 18, 1213, 2426, 3639, 7278, 10917, 21834.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21834: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
21834 is composite. Its prime factorisation is
- 3
The divisors add up to 47346; without 21834 itself that is 25512, so 21834 is abundant (25512 is more than 21834). Euler's totient φ(21834) = 7272 numbers up to 21834 share no factor with it.
- 4
The digits of 21834 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 162 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21834 = 2 \times 3^{2} \times 1213 \]21834 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 47346 |
| Euler totient φ(n) | 7272 |
| Square | 476723556 |
| Cube | 10408782121704 |
| Square root | 147.763324 (= 3√2426) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 162 |
| Scientific notation | 2.1834 × |
21834 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand eight hundred and thirty-four |
| Binary (base 2) | 101010101001010 |
| Octal (base 8) | 52512 |
| Hexadecimal (base 16) | 554A |
| Base 3 | 1002221200 |
| As time | 21834 seconds = 6 h 3 min 54 s |
Is 21834 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21834 ÷ 2 = 10917) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21834 ÷ 3 = 7278) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (21834 ÷ 6 = 3639) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (21834 ÷ 9 = 2426) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21834 a prime number?
No. 21834 = 2 × × 1213, so it is divisible by 2.
What are the factors of 21834?
1, 2, 3, 6, 9, 18, 1213, 2426, 3639, 7278, 10917, 21834.
What is 21834 in binary?
101010101001010 (hexadecimal 554A, octal 52512).
What is the square root of 21834?
About 147.7633, exactly 3√2426.
Is 21834 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 21834?
21834 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.