The number 1311
1311 is a composite number with 8 divisors. Its prime factorisation is 3 × 19 × 23. Divisors (8): 1, 3, 19, 23, 57, 69, 437, 1311.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
1311 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
1311 is composite. Its prime factorisation is
- 3
The divisors add up to 1920; without 1311 itself that is 609, so 1311 is deficient (609 is less than 1311). Euler's totient φ(1311) = 792 numbers up to 1311 share no factor with it.
- 4
The digits of 1311 add up to 6, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 101 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1311 = 3 \times 19 \times 23 \]
1311 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 1920 |
| Euler totient φ(n) | 792 |
| Square | 1718721 |
| Cube | 2253243231 |
| Square root | 36.207734 |
| Digit sum / digital root | 6 / 6 |
| Collatz steps to 1 | 101 |
| Scientific notation | 1.311 × |
1311 in other forms
| Form | Value |
|---|---|
| In words | one thousand three hundred and eleven |
| Roman numerals | MCCCXI |
| Binary (base 2) | 10100011111 |
| Octal (base 8) | 2437 |
| Hexadecimal (base 16) | 51F |
| Base 3 | 1210120 |
| As time | 1311 seconds = 21 min 51 s |
Is 1311 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 (1311 ÷ 3 = 437) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 6) | 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1311 a prime number?
No. 1311 = 3 × 19 × 23, so it is divisible by 3.
What are the factors of 1311?
1, 3, 19, 23, 57, 69, 437, 1311.
What is 1311 in binary?
10100011111 (hexadecimal 51F, octal 2437).
What is the square root of 1311?
About 36.2077.
What is 1311 in Roman numerals?
MCCCXI.
Is 1311 divisible by 3?
Yes. Its digits add up to 6, a multiple of 3.
What is special about the number 1311?
It is a composite number with 8 divisors.