The number 71841
71841 is a composite number with 16 divisors. Its prime factorisation is 3 × 7 × 11 × 311. Divisors (16): 1, 3, 7, 11, 21, 33, 77, 231, 311, 933, 2177, 3421, 6531, 10263, 23947, 71841.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71841: a Harshad number: divisible by its digit sum 21.
- 2
71841 is composite. Its prime factorisation is
- 3
The divisors add up to 119808; without 71841 itself that is 47967, so 71841 is deficient (47967 is less than 71841). Euler's totient φ(71841) = 37200 numbers up to 71841 share no factor with it.
- 4
The digits of 71841 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 187 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71841 = 3 \times 7 \times 11 \times 311 \]
71841 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 119808 |
| Euler totient φ(n) | 37200 |
| Square | 5161129281 |
| Cube | 370780688676321 |
| Square root | 268.031715 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 187 |
| Scientific notation | 7.1841 × |
71841 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand eight hundred and forty-one |
| Binary (base 2) | 10001100010100001 |
| Octal (base 8) | 214241 |
| Hexadecimal (base 16) | 118A1 |
| Base 3 | 10122112210 |
| As time | 71841 seconds = 19 h 57 min 21 s |
Is 71841 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 | Yes (71841 ÷ 3 = 23947) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (71841 ÷ 7 = 10263) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (71841 ÷ 11 = 6531) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 71841 a prime number?
No. 71841 = 3 × 7 × 11 × 311, so it is divisible by 3.
What are the factors of 71841?
1, 3, 7, 11, 21, 33, 77, 231, 311, 933, 2177, 3421, 6531, 10263, 23947, 71841.
What is 71841 in binary?
10001100010100001 (hexadecimal 118A1, octal 214241).
What is the square root of 71841?
About 268.0317.
Is 71841 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 71841?
71841 is a Harshad number: divisible by its digit sum 21.