The number 87040
87040 is a composite number with 44 divisors. Its prime factorisation is × 5 × 17. Divisors (44): 1, 2, 4, 5, 8, 10, 16, 17, 20, 32, 34, 40, 64, 68, 80, 85 … 87040.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87040: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
87040 is composite. Its prime factorisation is
- 3
The divisors add up to 221076; without 87040 itself that is 134036, so 87040 is abundant (134036 is more than 87040). Euler's totient φ(87040) = 32768 numbers up to 87040 share no factor with it.
- 4
The digits of 87040 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 19 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87040 = 2^{10} \times 5 \times 17 \]87040 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 44 |
| Sum of divisors | 221076 |
| Euler totient φ(n) | 32768 |
| Square | 7575961600 |
| Cube | 659411697664000 |
| Square root | 295.025423 (= 32√85) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 19 |
| Scientific notation | 8.704 × |
87040 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand and forty |
| Binary (base 2) | 10101010000000000 |
| Octal (base 8) | 252000 |
| Hexadecimal (base 16) | 15400 |
| Base 3 | 11102101201 |
| As time | 87040 seconds = 24 h 10 min 40 s |
Is 87040 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87040 ÷ 2 = 43520) | 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 | Yes (87040 ÷ 4 = 21760) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (87040 ÷ 5 = 17408) | 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 2) | 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 | Yes (87040 ÷ 8 = 10880) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (87040 ÷ 10 = 8704) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87040 a prime number?
No. 87040 = × 5 × 17, so it is divisible by 2.
What are the factors of 87040?
1, 2, 4, 5, 8, 10, 16, 17, 20, 32, 34, 40, 64, 68, 80, 85, 128, 136, 160, 170, 256, 272, 320, 340, 512, 544, 640, 680, 1024, 1088, 1280, 1360, 2176, 2560, 2720, 4352, 5120, 5440, 8704, 10880, 17408, 21760, 43520, 87040.
What is 87040 in binary?
10101010000000000 (hexadecimal 15400, octal 252000).
What is the square root of 87040?
About 295.0254, exactly 32√85.
Is 87040 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 87040?
87040 is a happy number: repeatedly adding the squares of its digits reaches 1.