The number 21882
21882 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 7 × 521. Divisors (16): 1, 2, 3, 6, 7, 14, 21, 42, 521, 1042, 1563, 3126, 3647, 7294, 10941, 21882.
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How to work it out
- 1
What is special about 21882: a Harshad number: divisible by its digit sum 21.
- 2
21882 is composite. Its prime factorisation is
- 3
The divisors add up to 50112; without 21882 itself that is 28230, so 21882 is abundant (28230 is more than 21882). Euler's totient φ(21882) = 6240 numbers up to 21882 share no factor with it.
- 4
The digits of 21882 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 162 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21882 = 2 \times 3 \times 7 \times 521 \]
21882 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 50112 |
| Euler totient φ(n) | 6240 |
| Square | 478821924 |
| Cube | 10477581340968 |
| Square root | 147.925657 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 162 |
| Scientific notation | 2.1882 × |
21882 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand eight hundred and eighty-two |
| Binary (base 2) | 101010101111010 |
| Octal (base 8) | 52572 |
| Hexadecimal (base 16) | 557A |
| Base 3 | 1010000110 |
| As time | 21882 seconds = 6 h 4 min 42 s |
Is 21882 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21882 ÷ 2 = 10941) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21882 ÷ 3 = 7294) | 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 | Yes (21882 ÷ 6 = 3647) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (21882 ÷ 7 = 3126) | 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 3) | 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 3) | 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 21882 a prime number?
No. 21882 = 2 × 3 × 7 × 521, so it is divisible by 2.
What are the factors of 21882?
1, 2, 3, 6, 7, 14, 21, 42, 521, 1042, 1563, 3126, 3647, 7294, 10941, 21882.
What is 21882 in binary?
101010101111010 (hexadecimal 557A, octal 52572).
What is the square root of 21882?
About 147.9257.
Is 21882 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 21882?
21882 is a Harshad number: divisible by its digit sum 21.