The number 80987
80987 is a composite number with 4 divisors. Its prime factorisation is 109 × 743. Divisors (4): 1, 109, 743, 80987.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 80987: a semiprime: 109 × 743, the product of two primes.
- 2
80987 is composite. Its prime factorisation is
- 3
The divisors add up to 81840; without 80987 itself that is 853, so 80987 is deficient (853 is less than 80987). Euler's totient φ(80987) = 80136 numbers up to 80987 share no factor with it.
- 4
The digits of 80987 add up to 32, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 182 steps to reach 1.
LaTeX source of the formulas on this page
\[ 80987 = 109 \times 743 \]
80987 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 81840 |
| Euler totient φ(n) | 80136 |
| Square | 6558894169 |
| Cube | 531185162064803 |
| Square root | 284.582150 |
| Digit sum / digital root | 32 / 5 |
| Collatz steps to 1 | 182 |
| Scientific notation | 8.0987 × |
80987 in other forms
| Form | Value |
|---|---|
| In words | eighty thousand nine hundred and eighty-seven |
| Binary (base 2) | 10011110001011011 |
| Octal (base 8) | 236133 |
| Hexadecimal (base 16) | 13C5B |
| Base 3 | 11010002112 |
| As time | 80987 seconds = 22 h 29 min 47 s |
Is 80987 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 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | 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 5) | 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 | No (remainder 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 80987 a prime number?
No. 80987 = 109 × 743, so it is divisible by 109.
What are the factors of 80987?
1, 109, 743, 80987.
What is 80987 in binary?
10011110001011011 (hexadecimal 13C5B, octal 236133).
What is the square root of 80987?
About 284.5821.
Is 80987 divisible by 3?
No. Its digits add up to 32, which is not a multiple of 3.
What is special about the number 80987?
80987 is a semiprime: 109 × 743, the product of two primes.