The number 3665
3665 is a composite number with 4 divisors. Its prime factorisation is 5 × 733. Divisors (4): 1, 5, 733, 3665.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 3665: a semiprime: 5 × 733, the product of two primes.
- 2
3665 is composite. Its prime factorisation is
- 3
The divisors add up to 4404; without 3665 itself that is 739, so 3665 is deficient (739 is less than 3665). Euler's totient φ(3665) = 2928 numbers up to 3665 share no factor with it.
- 4
The digits of 3665 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 43 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3665 = 5 \times 733 \]
3665 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 4404 |
| Euler totient φ(n) | 2928 |
| Square | 13432225 |
| Cube | 49229104625 |
| Square root | 60.539243 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 43 |
| Scientific notation | 3.665 × |
3665 in other forms
| Form | Value |
|---|---|
| In words | three thousand six hundred and sixty-five |
| Roman numerals | MMMDCLXV |
| Binary (base 2) | 111001010001 |
| Octal (base 8) | 7121 |
| Hexadecimal (base 16) | E51 |
| Base 3 | 12000202 |
| As time | 3665 seconds = 1 h 1 min 5 s |
Is 3665 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 (3665 ÷ 5 = 733) | 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 | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 3665 a prime number?
No. 3665 = 5 × 733, so it is divisible by 5.
What are the factors of 3665?
1, 5, 733, 3665.
What is 3665 in binary?
111001010001 (hexadecimal E51, octal 7121).
What is the square root of 3665?
About 60.5392.
What is 3665 in Roman numerals?
MMMDCLXV.
Is 3665 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 3665?
3665 is a semiprime: 5 × 733, the product of two primes.