The number 81744
81744 is a composite number with 40 divisors. Its prime factorisation is × 3 × 13 × 131. Divisors (40): 1, 2, 3, 4, 6, 8, 12, 13, 16, 24, 26, 39, 48, 52, 78, 104 … 81744.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 81744: a Harshad number: divisible by its digit sum 24.
- 2
81744 is composite. Its prime factorisation is
- 3
The divisors add up to 229152; without 81744 itself that is 147408, so 81744 is abundant (147408 is more than 81744). Euler's totient φ(81744) = 24960 numbers up to 81744 share no factor with it.
- 4
The digits of 81744 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 63 steps to reach 1.
LaTeX source of the formulas on this page
\[ 81744 = 2^{4} \times 3 \times 13 \times 131 \]81744 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 40 |
| Sum of divisors | 229152 |
| Euler totient φ(n) | 24960 |
| Square | 6682081536 |
| Cube | 546220073078784 |
| Square root | 285.909076 (= 4√5109) |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 63 |
| Scientific notation | 8.1744 × |
81744 in other forms
| Form | Value |
|---|---|
| In words | eighty-one thousand seven hundred and forty-four |
| Binary (base 2) | 10011111101010000 |
| Octal (base 8) | 237520 |
| Hexadecimal (base 16) | 13F50 |
| Base 3 | 11011010120 |
| As time | 81744 seconds = 22 h 42 min 24 s |
Is 81744 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (81744 ÷ 2 = 40872) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (81744 ÷ 3 = 27248) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (81744 ÷ 4 = 20436) | 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 | Yes (81744 ÷ 6 = 13624) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 (81744 ÷ 8 = 10218) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (81744 ÷ 12 = 6812) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 81744 a prime number?
No. 81744 = × 3 × 13 × 131, so it is divisible by 2.
What are the factors of 81744?
1, 2, 3, 4, 6, 8, 12, 13, 16, 24, 26, 39, 48, 52, 78, 104, 131, 156, 208, 262, 312, 393, 524, 624, 786, 1048, 1572, 1703, 2096, 3144, 3406, 5109, 6288, 6812, 10218, 13624, 20436, 27248, 40872, 81744.
What is 81744 in binary?
10011111101010000 (hexadecimal 13F50, octal 237520).
What is the square root of 81744?
About 285.9091, exactly 4√5109.
Is 81744 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 81744?
81744 is a Harshad number: divisible by its digit sum 24.