The number 87140
87140 is a composite number with 12 divisors. Its prime factorisation is × 5 × 4357. Divisors (12): 1, 2, 4, 5, 10, 20, 4357, 8714, 17428, 21785, 43570, 87140.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87140: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 20.
- 2
87140 is composite. Its prime factorisation is
- 3
The divisors add up to 183036; without 87140 itself that is 95896, so 87140 is abundant (95896 is more than 87140). Euler's totient φ(87140) = 34848 numbers up to 87140 share no factor with it.
- 4
The digits of 87140 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 71 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87140 = 2^{2} \times 5 \times 4357 \]87140 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 183036 |
| Euler totient φ(n) | 34848 |
| Square | 7593379600 |
| Cube | 661687098344000 |
| Square root | 295.194851 (= 2√21785) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 71 |
| Scientific notation | 8.714 × |
87140 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand one hundred and forty |
| Binary (base 2) | 10101010001100100 |
| Octal (base 8) | 252144 |
| Hexadecimal (base 16) | 15464 |
| Base 3 | 11102112102 |
| As time | 87140 seconds = 24 h 12 min 20 s |
Is 87140 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87140 ÷ 2 = 43570) | 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 | Yes (87140 ÷ 4 = 21785) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (87140 ÷ 5 = 17428) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (87140 ÷ 10 = 8714) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87140 a prime number?
No. 87140 = × 5 × 4357, so it is divisible by 2.
What are the factors of 87140?
1, 2, 4, 5, 10, 20, 4357, 8714, 17428, 21785, 43570, 87140.
What is 87140 in binary?
10101010001100100 (hexadecimal 15464, octal 252144).
What is the square root of 87140?
About 295.1949, exactly 2√21785.
Is 87140 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 87140?
87140 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 20.