The number 87042
87042 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 89 × 163. Divisors (16): 1, 2, 3, 6, 89, 163, 178, 267, 326, 489, 534, 978, 14507, 29014, 43521, 87042.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87042: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
87042 is composite. Its prime factorisation is
- 3
The divisors add up to 177120; without 87042 itself that is 90078, so 87042 is abundant (90078 is more than 87042). Euler's totient φ(87042) = 28512 numbers up to 87042 share no factor with it.
- 4
The digits of 87042 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 71 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87042 = 2 \times 3 \times 89 \times 163 \]
87042 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 177120 |
| Euler totient φ(n) | 28512 |
| Square | 7576309764 |
| Cube | 659457154478088 |
| Square root | 295.028812 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 71 |
| Scientific notation | 8.7042 × |
87042 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand and forty-two |
| Binary (base 2) | 10101010000000010 |
| Octal (base 8) | 252002 |
| Hexadecimal (base 16) | 15402 |
| Base 3 | 11102101210 |
| As time | 87042 seconds = 24 h 10 min 42 s |
Is 87042 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87042 ÷ 2 = 43521) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (87042 ÷ 3 = 29014) | 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 | Yes (87042 ÷ 6 = 14507) | 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 2) | 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 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87042 a prime number?
No. 87042 = 2 × 3 × 89 × 163, so it is divisible by 2.
What are the factors of 87042?
1, 2, 3, 6, 89, 163, 178, 267, 326, 489, 534, 978, 14507, 29014, 43521, 87042.
What is 87042 in binary?
10101010000000010 (hexadecimal 15402, octal 252002).
What is the square root of 87042?
About 295.0288.
Is 87042 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 87042?
87042 is a happy number: repeatedly adding the squares of its digits reaches 1.