The number 87982
87982 is a composite number with 4 divisors. Its prime factorisation is 2 × 43991. Divisors (4): 1, 2, 43991, 87982.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87982: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 43991, the product of two primes.
- 2
87982 is composite. Its prime factorisation is
- 3
The divisors add up to 131976; without 87982 itself that is 43994, so 87982 is deficient (43994 is less than 87982). Euler's totient φ(87982) = 43990 numbers up to 87982 share no factor with it.
- 4
The digits of 87982 add up to 34, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 151 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87982 = 2 \times 43991 \]
87982 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 131976 |
| Euler totient φ(n) | 43990 |
| Square | 7740832324 |
| Cube | 681053909530168 |
| Square root | 296.617599 |
| Digit sum / digital root | 34 / 7 |
| Collatz steps to 1 | 151 |
| Scientific notation | 8.7982 × |
87982 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand nine hundred and eighty-two |
| Binary (base 2) | 10101011110101110 |
| Octal (base 8) | 253656 |
| Hexadecimal (base 16) | 157AE |
| Base 3 | 11110200121 |
| As time | 87982 seconds = 24 h 26 min 22 s |
Is 87982 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87982 ÷ 2 = 43991) | 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 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 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 | No (remainder 7) | 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 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87982 a prime number?
No. 87982 = 2 × 43991, so it is divisible by 2.
What are the factors of 87982?
1, 2, 43991, 87982.
What is 87982 in binary?
10101011110101110 (hexadecimal 157AE, octal 253656).
What is the square root of 87982?
About 296.6176.
Is 87982 divisible by 3?
No. Its digits add up to 34, which is not a multiple of 3.
What is special about the number 87982?
87982 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 43991, the product of two primes.