The number 21182
21182 is a composite number with 16 divisors. Its prime factorisation is 2 × 7 × 17 × 89. Divisors (16): 1, 2, 7, 14, 17, 34, 89, 119, 178, 238, 623, 1246, 1513, 3026, 10591, 21182.
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How to work it out
- 1
What is special about 21182: a Harshad number: divisible by its digit sum 14.
- 2
21182 is composite. Its prime factorisation is
- 3
The divisors add up to 38880; without 21182 itself that is 17698, so 21182 is deficient (17698 is less than 21182). Euler's totient φ(21182) = 8448 numbers up to 21182 share no factor with it.
- 4
The digits of 21182 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 149 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21182 = 2 \times 7 \times 17 \times 89 \]
21182 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 38880 |
| Euler totient φ(n) | 8448 |
| Square | 448677124 |
| Cube | 9503878840568 |
| Square root | 145.540372 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 149 |
| Scientific notation | 2.1182 × |
21182 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand one hundred and eighty-two |
| Binary (base 2) | 101001010111110 |
| Octal (base 8) | 51276 |
| Hexadecimal (base 16) | 52BE |
| Base 3 | 1002001112 |
| As time | 21182 seconds = 5 h 53 min 2 s |
Is 21182 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21182 ÷ 2 = 10591) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | 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 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (21182 ÷ 7 = 3026) | 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 5) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21182 a prime number?
No. 21182 = 2 × 7 × 17 × 89, so it is divisible by 2.
What are the factors of 21182?
1, 2, 7, 14, 17, 34, 89, 119, 178, 238, 623, 1246, 1513, 3026, 10591, 21182.
What is 21182 in binary?
101001010111110 (hexadecimal 52BE, octal 51276).
What is the square root of 21182?
About 145.5404.
Is 21182 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 21182?
21182 is a Harshad number: divisible by its digit sum 14.