The number 81342
81342 is a composite number with 12 divisors. Its prime factorisation is 2 × × 4519. Divisors (12): 1, 2, 3, 6, 9, 18, 4519, 9038, 13557, 27114, 40671, 81342.
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How to work it out
- 1
What is special about 81342: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
81342 is composite. Its prime factorisation is
- 3
The divisors add up to 176280; without 81342 itself that is 94938, so 81342 is abundant (94938 is more than 81342). Euler's totient φ(81342) = 27108 numbers up to 81342 share no factor with it.
- 4
The digits of 81342 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 182 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81342 = 2 \times 3^{2} \times 4519 \]81342 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 176280 |
| Euler totient φ(n) | 27108 |
| Square | 6616520964 |
| Cube | 538201048253688 |
| Square root | 285.205189 (= 3√9038) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 182 |
| Scientific notation | 8.1342 × |
81342 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand three hundred and forty-two |
| Binary (base 2) | 10011110110111110 |
| Octal (base 8) | 236676 |
| Hexadecimal (base 16) | 13DBE |
| Base 3 | 11010120200 |
| As time | 81342 seconds = 22 h 35 min 42 s |
Is 81342 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (81342 ÷ 2 = 40671) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (81342 ÷ 3 = 27114) | 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 (81342 ÷ 6 = 13557) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 | Yes (81342 ÷ 9 = 9038) | 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 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81342 a prime number?
No. 81342 = 2 × × 4519, so it is divisible by 2.
What are the factors of 81342?
1, 2, 3, 6, 9, 18, 4519, 9038, 13557, 27114, 40671, 81342.
What is 81342 in binary?
10011110110111110 (hexadecimal 13DBE, octal 236676).
What is the square root of 81342?
About 285.2052, exactly 3√9038.
Is 81342 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 81342?
81342 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.