The number 71982
71982 is a composite number with 32 divisors. Its prime factorisation is 2 × × 31 × 43. Divisors (32): 1, 2, 3, 6, 9, 18, 27, 31, 43, 54, 62, 86, 93, 129, 186, 258 … 71982.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71982: a Harshad number: divisible by its digit sum 27.
- 2
71982 is composite. Its prime factorisation is
- 3
The divisors add up to 168960; without 71982 itself that is 96978, so 71982 is abundant (96978 is more than 71982). Euler's totient φ(71982) = 22680 numbers up to 71982 share no factor with it.
- 4
The digits of 71982 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 50 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71982 = 2 \times 3^{3} \times 31 \times 43 \]71982 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 168960 |
| Euler totient φ(n) | 22680 |
| Square | 5181408324 |
| Cube | 372968133978168 |
| Square root | 268.294614 (= 3√7998) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 50 |
| Scientific notation | 7.1982 × |
71982 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand nine hundred and eighty-two |
| Binary (base 2) | 10001100100101110 |
| Octal (base 8) | 214456 |
| Hexadecimal (base 16) | 1192E |
| Base 3 | 10122202000 |
| As time | 71982 seconds = 19 h 59 min 42 s |
Is 71982 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (71982 ÷ 2 = 35991) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (71982 ÷ 3 = 23994) | 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 (71982 ÷ 6 = 11997) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 (71982 ÷ 9 = 7998) | 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 9) | 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 71982 a prime number?
No. 71982 = 2 × × 31 × 43, so it is divisible by 2.
What are the factors of 71982?
1, 2, 3, 6, 9, 18, 27, 31, 43, 54, 62, 86, 93, 129, 186, 258, 279, 387, 558, 774, 837, 1161, 1333, 1674, 2322, 2666, 3999, 7998, 11997, 23994, 35991, 71982.
What is 71982 in binary?
10001100100101110 (hexadecimal 1192E, octal 214456).
What is the square root of 71982?
About 268.2946, exactly 3√7998.
Is 71982 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 71982?
71982 is a Harshad number: divisible by its digit sum 27.