The number 42665
42665 is a composite number with 16 divisors. Its prime factorisation is 5 × 7 × 23 × 53. Divisors (16): 1, 5, 7, 23, 35, 53, 115, 161, 265, 371, 805, 1219, 1855, 6095, 8533, 42665.
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How to work it out
- 1
What is special about 42665: a Harshad number: divisible by its digit sum 23.
- 2
42665 is composite. Its prime factorisation is
- 3
The divisors add up to 62208; without 42665 itself that is 19543, so 42665 is deficient (19543 is less than 42665). Euler's totient φ(42665) = 27456 numbers up to 42665 share no factor with it.
- 4
The digits of 42665 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 101 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42665 = 5 \times 7 \times 23 \times 53 \]
42665 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 62208 |
| Euler totient φ(n) | 27456 |
| Square | 1820302225 |
| Cube | 77663194429625 |
| Square root | 206.555077 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 101 |
| Scientific notation | 4.2665 × |
42665 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand six hundred and sixty-five |
| Binary (base 2) | 1010011010101001 |
| Octal (base 8) | 123251 |
| Hexadecimal (base 16) | A6A9 |
| Base 3 | 2011112012 |
| As time | 42665 seconds = 11 h 51 min 5 s |
Is 42665 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 | No (remainder 2) | 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 (42665 ÷ 5 = 8533) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (42665 ÷ 7 = 6095) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42665 a prime number?
No. 42665 = 5 × 7 × 23 × 53, so it is divisible by 5.
What are the factors of 42665?
1, 5, 7, 23, 35, 53, 115, 161, 265, 371, 805, 1219, 1855, 6095, 8533, 42665.
What is 42665 in binary?
1010011010101001 (hexadecimal A6A9, octal 123251).
What is the square root of 42665?
About 206.5551.
Is 42665 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 42665?
42665 is a Harshad number: divisible by its digit sum 23.