The number 87987
87987 is a composite number with 8 divisors. Its prime factorisation is 3 × 139 × 211. Divisors (8): 1, 3, 139, 211, 417, 633, 29329, 87987.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
87987 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
87987 is composite. Its prime factorisation is
- 3
The divisors add up to 118720; without 87987 itself that is 30733, so 87987 is deficient (30733 is less than 87987). Euler's totient φ(87987) = 57960 numbers up to 87987 share no factor with it.
- 4
The digits of 87987 add up to 39, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 133 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87987 = 3 \times 139 \times 211 \]
87987 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 118720 |
| Euler totient φ(n) | 57960 |
| Square | 7741712169 |
| Cube | 681170028613803 |
| Square root | 296.626027 |
| Digit sum / digital root | 39 / 3 |
| Collatz steps to 1 | 133 |
| Scientific notation | 8.7987 × |
87987 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand nine hundred and eighty-seven |
| Binary (base 2) | 10101011110110011 |
| Octal (base 8) | 253663 |
| Hexadecimal (base 16) | 157B3 |
| Base 3 | 11110200210 |
| As time | 87987 seconds = 24 h 26 min 27 s |
Is 87987 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 (87987 ÷ 3 = 29329) | 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 3) | 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 3) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87987 a prime number?
No. 87987 = 3 × 139 × 211, so it is divisible by 3.
What are the factors of 87987?
1, 3, 139, 211, 417, 633, 29329, 87987.
What is 87987 in binary?
10101011110110011 (hexadecimal 157B3, octal 253663).
What is the square root of 87987?
About 296.6260.
Is 87987 divisible by 3?
Yes. Its digits add up to 39, a multiple of 3.
What is special about the number 87987?
It is a composite number with 8 divisors.