The number 21832
21832 is a composite number with 8 divisors. Its prime factorisation is × 2729. Divisors (8): 1, 2, 4, 8, 2729, 5458, 10916, 21832.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21832: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
21832 is composite. Its prime factorisation is
- 3
The divisors add up to 40950; without 21832 itself that is 19118, so 21832 is deficient (19118 is less than 21832). Euler's totient φ(21832) = 10912 numbers up to 21832 share no factor with it.
- 4
The digits of 21832 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 162 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21832 = 2^{3} \times 2729 \]21832 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 40950 |
| Euler totient φ(n) | 10912 |
| Square | 476636224 |
| Cube | 10405922042368 |
| Square root | 147.756557 (= 2√5458) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 162 |
| Scientific notation | 2.1832 × |
21832 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand eight hundred and thirty-two |
| Binary (base 2) | 101010101001000 |
| Octal (base 8) | 52510 |
| Hexadecimal (base 16) | 5548 |
| Base 3 | 1002221121 |
| As time | 21832 seconds = 6 h 3 min 52 s |
Is 21832 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21832 ÷ 2 = 10916) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (21832 ÷ 4 = 5458) | 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 4) | 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 (21832 ÷ 8 = 2729) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21832 a prime number?
No. 21832 = × 2729, so it is divisible by 2.
What are the factors of 21832?
1, 2, 4, 8, 2729, 5458, 10916, 21832.
What is 21832 in binary?
101010101001000 (hexadecimal 5548, octal 52510).
What is the square root of 21832?
About 147.7566, exactly 2√5458.
Is 21832 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 21832?
21832 is a happy number: repeatedly adding the squares of its digits reaches 1.