The number 42165
42165 is a composite number with 12 divisors. Its prime factorisation is × 5 × 937. Divisors (12): 1, 3, 5, 9, 15, 45, 937, 2811, 4685, 8433, 14055, 42165.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42165: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
42165 is composite. Its prime factorisation is
- 3
The divisors add up to 73164; without 42165 itself that is 30999, so 42165 is deficient (30999 is less than 42165). Euler's totient φ(42165) = 22464 numbers up to 42165 share no factor with it.
- 4
The digits of 42165 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 57 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42165 = 3^{2} \times 5 \times 937 \]42165 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 73164 |
| Euler totient φ(n) | 22464 |
| Square | 1777887225 |
| Cube | 74964614842125 |
| Square root | 205.341180 (= 3√4685) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 57 |
| Scientific notation | 4.2165 × |
42165 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand one hundred and sixty-five |
| Binary (base 2) | 1010010010110101 |
| Octal (base 8) | 122265 |
| Hexadecimal (base 16) | A4B5 |
| Base 3 | 2010211200 |
| As time | 42165 seconds = 11 h 42 min 45 s |
Is 42165 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 (42165 ÷ 3 = 14055) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (42165 ÷ 5 = 8433) | 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 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (42165 ÷ 9 = 4685) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42165 a prime number?
No. 42165 = × 5 × 937, so it is divisible by 3.
What are the factors of 42165?
1, 3, 5, 9, 15, 45, 937, 2811, 4685, 8433, 14055, 42165.
What is 42165 in binary?
1010010010110101 (hexadecimal A4B5, octal 122265).
What is the square root of 42165?
About 205.3412, exactly 3√4685.
Is 42165 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 42165?
42165 is a happy number: repeatedly adding the squares of its digits reaches 1.