The number 3681
3681 is a composite number with 6 divisors. Its prime factorisation is × 409. Divisors (6): 1, 3, 9, 409, 1227, 3681.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
3681 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
3681 is composite. Its prime factorisation is
- 3
The divisors add up to 5330; without 3681 itself that is 1649, so 3681 is deficient (1649 is less than 3681). Euler's totient φ(3681) = 2448 numbers up to 3681 share no factor with it.
- 4
The digits of 3681 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 131 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3681 = 3^{2} \times 409 \]3681 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 5330 |
| Euler totient φ(n) | 2448 |
| Square | 13549761 |
| Cube | 49876670241 |
| Square root | 60.671245 (= 3√409) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 131 |
| Scientific notation | 3.681 × |
3681 in other forms
| Form | Value |
|---|---|
| In words | three thousand six hundred and eighty-one |
| Roman numerals | MMMDCLXXXI |
| Binary (base 2) | 111001100001 |
| Octal (base 8) | 7141 |
| Hexadecimal (base 16) | E61 |
| Base 3 | 12001100 |
| As time | 3681 seconds = 1 h 1 min 21 s |
Is 3681 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 (3681 ÷ 3 = 1227) | 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 | No (remainder 1) | 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 6) | 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 | Yes (3681 ÷ 9 = 409) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 3681 a prime number?
No. 3681 = × 409, so it is divisible by 3.
What are the factors of 3681?
1, 3, 9, 409, 1227, 3681.
What is 3681 in binary?
111001100001 (hexadecimal E61, octal 7141).
What is the square root of 3681?
About 60.6712, exactly 3√409.
What is 3681 in Roman numerals?
MMMDCLXXXI.
Is 3681 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 3681?
It is a composite number with 6 divisors.