The number 21846
21846 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 11 × 331. Divisors (16): 1, 2, 3, 6, 11, 22, 33, 66, 331, 662, 993, 1986, 3641, 7282, 10923, 21846.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21846 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21846 is composite. Its prime factorisation is
- 3
The divisors add up to 47808; without 21846 itself that is 25962, so 21846 is abundant (25962 is more than 21846). Euler's totient φ(21846) = 6600 numbers up to 21846 share no factor with it.
- 4
The digits of 21846 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 56 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21846 = 2 \times 3 \times 11 \times 331 \]
21846 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 47808 |
| Euler totient φ(n) | 6600 |
| Square | 477247716 |
| Cube | 10425953603736 |
| Square root | 147.803924 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 56 |
| Scientific notation | 2.1846 × |
21846 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand eight hundred and forty-six |
| Binary (base 2) | 101010101010110 |
| Octal (base 8) | 52526 |
| Hexadecimal (base 16) | 5556 |
| Base 3 | 1002222010 |
| As time | 21846 seconds = 6 h 4 min 6 s |
Is 21846 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21846 ÷ 2 = 10923) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21846 ÷ 3 = 7282) | 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 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (21846 ÷ 6 = 3641) | 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 | No (remainder 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 6) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (21846 ÷ 11 = 1986) | 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 21846 a prime number?
No. 21846 = 2 × 3 × 11 × 331, so it is divisible by 2.
What are the factors of 21846?
1, 2, 3, 6, 11, 22, 33, 66, 331, 662, 993, 1986, 3641, 7282, 10923, 21846.
What is 21846 in binary?
101010101010110 (hexadecimal 5556, octal 52526).
What is the square root of 21846?
About 147.8039.
Is 21846 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 21846?
It is a composite number with 16 divisors.