The number 3181
3181 is the 450th prime number. Its only divisors are 1 and 3181.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 3181: the 450th prime number.
- 2
3181 is prime, so its only factors are 1 and 3181. It is the 450th prime; the next prime is 3187 and the one before is 3169.
- 3
The divisors add up to 3182; without 3181 itself that is 1, so 3181 is deficient (1 is less than 3181). Euler's totient φ(3181) = 3180 numbers up to 3181 share no factor with it.
- 4
The digits of 3181 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 105 steps to reach 1.
3181 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 3182 |
| Euler totient φ(n) | 3180 |
| Square | 10118761 |
| Cube | 32187778741 |
| Square root | 56.400355 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 105 |
| Scientific notation | 3.181 × |
3181 in other forms
| Form | Value |
|---|---|
| In words | three thousand one hundred and eighty-one |
| Roman numerals | MMMCLXXXI |
| Binary (base 2) | 110001101101 |
| Octal (base 8) | 6155 |
| Hexadecimal (base 16) | C6D |
| Base 3 | 11100211 |
| As time | 3181 seconds = 53 min 1 s |
Is 3181 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 1) | 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 1) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 3181 a prime number?
Yes. 3181 is divisible only by 1 and itself.
What are the factors of 3181?
1, 3181.
What is 3181 in binary?
110001101101 (hexadecimal C6D, octal 6155).
What is the square root of 3181?
About 56.4004.
What is 3181 in Roman numerals?
MMMCLXXXI.
Is 3181 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 3181?
3181 is the 450th prime number.