The number 42087
42087 is a composite number with 4 divisors. Its prime factorisation is 3 × 14029. Divisors (4): 1, 3, 14029, 42087.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42087: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 3 × 14029, the product of two primes.
- 2
42087 is composite. Its prime factorisation is
- 3
The divisors add up to 56120; without 42087 itself that is 14033, so 42087 is deficient (14033 is less than 42087). Euler's totient φ(42087) = 28056 numbers up to 42087 share no factor with it.
- 4
The digits of 42087 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 150 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42087 = 3 \times 14029 \]
42087 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 56120 |
| Euler totient φ(n) | 28056 |
| Square | 1771315569 |
| Cube | 74549358352503 |
| Square root | 205.151164 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 150 |
| Scientific notation | 4.2087 × |
42087 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand and eighty-seven |
| Binary (base 2) | 1010010001100111 |
| Octal (base 8) | 122147 |
| Hexadecimal (base 16) | A467 |
| Base 3 | 2010201210 |
| As time | 42087 seconds = 11 h 41 min 27 s |
Is 42087 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 (42087 ÷ 3 = 14029) | 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 3) | 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 7) | 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 1) | 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 42087 a prime number?
No. 42087 = 3 × 14029, so it is divisible by 3.
What are the factors of 42087?
1, 3, 14029, 42087.
What is 42087 in binary?
1010010001100111 (hexadecimal A467, octal 122147).
What is the square root of 42087?
About 205.1512.
Is 42087 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 42087?
42087 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 3 × 14029, the product of two primes.