The number 87442
87442 is a composite number with 4 divisors. Its prime factorisation is 2 × 43721. Divisors (4): 1, 2, 43721, 87442.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 87442: a semiprime: 2 × 43721, the product of two primes.
- 2
87442 is composite. Its prime factorisation is
- 3
The divisors add up to 131166; without 87442 itself that is 43724, so 87442 is deficient (43724 is less than 87442). Euler's totient φ(87442) = 43720 numbers up to 87442 share no factor with it.
- 4
The digits of 87442 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 120 steps to reach 1.
LaTeX source of the formulas on this page
\[ 87442 = 2 \times 43721 \]
87442 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 131166 |
| Euler totient φ(n) | 43720 |
| Square | 7646103364 |
| Cube | 668590570354888 |
| Square root | 295.705935 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 120 |
| Scientific notation | 8.7442 × |
87442 in other forms
| Form | Value |
|---|---|
| In words | eighty-seven thousand four hundred and forty-two |
| Binary (base 2) | 10101010110010010 |
| Octal (base 8) | 252622 |
| Hexadecimal (base 16) | 15592 |
| Base 3 | 11102221121 |
| As time | 87442 seconds = 24 h 17 min 22 s |
Is 87442 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (87442 ÷ 2 = 43721) | 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 | 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 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 7) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 87442 a prime number?
No. 87442 = 2 × 43721, so it is divisible by 2.
What are the factors of 87442?
1, 2, 43721, 87442.
What is 87442 in binary?
10101010110010010 (hexadecimal 15592, octal 252622).
What is the square root of 87442?
About 295.7059.
Is 87442 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 87442?
87442 is a semiprime: 2 × 43721, the product of two primes.