The number 81427
81427 is a composite number with 4 divisors. Its prime factorisation is 107 × 761. Divisors (4): 1, 107, 761, 81427.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 81427: a semiprime: 107 × 761, the product of two primes.
- 2
81427 is composite. Its prime factorisation is
- 3
The divisors add up to 82296; without 81427 itself that is 869, so 81427 is deficient (869 is less than 81427). Euler's totient φ(81427) = 80560 numbers up to 81427 share no factor with it.
- 4
The digits of 81427 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 195 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81427 = 107 \times 761 \]
81427 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 82296 |
| Euler totient φ(n) | 80560 |
| Square | 6630356329 |
| Cube | 539890024801483 |
| Square root | 285.354166 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 195 |
| Scientific notation | 8.1427 × |
81427 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand four hundred and twenty-seven |
| Binary (base 2) | 10011111000010011 |
| Octal (base 8) | 237023 |
| Hexadecimal (base 16) | 13E13 |
| Base 3 | 11010200211 |
| As time | 81427 seconds = 22 h 37 min 7 s |
Is 81427 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | 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 3) | 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 1) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81427 a prime number?
No. 81427 = 107 × 761, so it is divisible by 107.
What are the factors of 81427?
1, 107, 761, 81427.
What is 81427 in binary?
10011111000010011 (hexadecimal 13E13, octal 237023).
What is the square root of 81427?
About 285.3542.
Is 81427 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 81427?
81427 is a semiprime: 107 × 761, the product of two primes.