The number 81344
81344 is a composite number with 28 divisors. Its prime factorisation is × 31 × 41. Divisors (28): 1, 2, 4, 8, 16, 31, 32, 41, 62, 64, 82, 124, 164, 248, 328, 496 … 81344.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
81344 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
81344 is composite. Its prime factorisation is
- 3
The divisors add up to 170688; without 81344 itself that is 89344, so 81344 is abundant (89344 is more than 81344). Euler's totient φ(81344) = 38400 numbers up to 81344 share no factor with it.
- 4
The digits of 81344 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 37 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81344 = 2^{6} \times 31 \times 41 \]81344 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 28 |
| Sum of divisors | 170688 |
| Euler totient φ(n) | 38400 |
| Square | 6616846336 |
| Cube | 538240748355584 |
| Square root | 285.208696 (= 8√1271) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 37 |
| Scientific notation | 8.1344 × |
81344 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand three hundred and forty-four |
| Binary (base 2) | 10011110111000000 |
| Octal (base 8) | 236700 |
| Hexadecimal (base 16) | 13DC0 |
| Base 3 | 11010120202 |
| As time | 81344 seconds = 22 h 35 min 44 s |
Is 81344 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (81344 ÷ 2 = 40672) | 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 | Yes (81344 ÷ 4 = 20336) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 | No (remainder 4) | 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 | Yes (81344 ÷ 8 = 10168) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81344 a prime number?
No. 81344 = × 31 × 41, so it is divisible by 2.
What are the factors of 81344?
1, 2, 4, 8, 16, 31, 32, 41, 62, 64, 82, 124, 164, 248, 328, 496, 656, 992, 1271, 1312, 1984, 2542, 2624, 5084, 10168, 20336, 40672, 81344.
What is 81344 in binary?
10011110111000000 (hexadecimal 13DC0, octal 236700).
What is the square root of 81344?
About 285.2087, exactly 8√1271.
Is 81344 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 81344?
It is a composite number with 28 divisors.