The number 21682
21682 is a composite number with 8 divisors. Its prime factorisation is 2 × 37 × 293. Divisors (8): 1, 2, 37, 74, 293, 586, 10841, 21682.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21682: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
21682 is composite. Its prime factorisation is
- 3
The divisors add up to 33516; without 21682 itself that is 11834, so 21682 is deficient (11834 is less than 21682). Euler's totient φ(21682) = 10512 numbers up to 21682 share no factor with it.
- 4
The digits of 21682 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 131 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21682 = 2 \times 37 \times 293 \]
21682 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 33516 |
| Euler totient φ(n) | 10512 |
| Square | 470109124 |
| Cube | 10192906026568 |
| Square root | 147.248090 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 131 |
| Scientific notation | 2.1682 × |
21682 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand six hundred and eighty-two |
| Binary (base 2) | 101010010110010 |
| Octal (base 8) | 52262 |
| Hexadecimal (base 16) | 54B2 |
| Base 3 | 1002202001 |
| As time | 21682 seconds = 6 h 1 min 22 s |
Is 21682 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21682 ÷ 2 = 10841) | 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 | No (remainder 2) | 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 3) | 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 | No (remainder 1) | 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 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21682 a prime number?
No. 21682 = 2 × 37 × 293, so it is divisible by 2.
What are the factors of 21682?
1, 2, 37, 74, 293, 586, 10841, 21682.
What is 21682 in binary?
101010010110010 (hexadecimal 54B2, octal 52262).
What is the square root of 21682?
About 147.2481.
Is 21682 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 21682?
21682 is a happy number: repeatedly adding the squares of its digits reaches 1.