The number 3391
3391 is a twin prime (3389 and 3391 are both prime) and the 478th prime number. Its only divisors are 1 and 3391.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 3391: a twin prime (3389 and 3391 are both prime); the 478th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
3391 is prime, so its only factors are 1 and 3391. It is the 478th prime; the next prime is 3407 and the one before is 3389.
- 3
The divisors add up to 3392; without 3391 itself that is 1, so 3391 is deficient (1 is less than 3391). Euler's totient φ(3391) = 3390 numbers up to 3391 share no factor with it.
- 4
The digits of 3391 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 180 steps to reach 1.
3391 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 3392 |
| Euler totient φ(n) | 3390 |
| Square | 11498881 |
| Cube | 38992705471 |
| Square root | 58.232293 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 180 |
| Scientific notation | 3.391 × |
3391 in other forms
| Form | Value |
|---|---|
| In words | three thousand three hundred and ninety-one |
| Roman numerals | MMMCCCXCI |
| Binary (base 2) | 110100111111 |
| Octal (base 8) | 6477 |
| Hexadecimal (base 16) | D3F |
| Base 3 | 11122121 |
| As time | 3391 seconds = 56 min 31 s |
Is 3391 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 3) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 3391 a prime number?
Yes. 3391 is divisible only by 1 and itself.
What are the factors of 3391?
1, 3391.
What is 3391 in binary?
110100111111 (hexadecimal D3F, octal 6477).
What is the square root of 3391?
About 58.2323.
What is 3391 in Roman numerals?
MMMCCCXCI.
Is 3391 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 3391?
3391 is a twin prime (3389 and 3391 are both prime); the 478th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.