The number 4191
4191 is a composite number with 8 divisors. Its prime factorisation is 3 × 11 × 127. Divisors (8): 1, 3, 11, 33, 127, 381, 1397, 4191.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
4191 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
4191 is composite. Its prime factorisation is
- 3
The divisors add up to 6144; without 4191 itself that is 1953, so 4191 is deficient (1953 is less than 4191). Euler's totient φ(4191) = 2520 numbers up to 4191 share no factor with it.
- 4
The digits of 4191 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 108 steps to reach 1.
LaTeX source of the formulas on this page
\[ 4191 = 3 \times 11 \times 127 \]
4191 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 6144 |
| Euler totient φ(n) | 2520 |
| Square | 17564481 |
| Cube | 73612739871 |
| Square root | 64.737933 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 108 |
| Scientific notation | 4.191 × |
4191 in other forms
| Form | Value |
|---|---|
| In words | four thousand one hundred and ninety-one |
| Binary (base 2) | 1000001011111 |
| Octal (base 8) | 10137 |
| Hexadecimal (base 16) | 105F |
| Base 3 | 12202020 |
| As time | 4191 seconds = 1 h 9 min 51 s |
Is 4191 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 (4191 ÷ 3 = 1397) | 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 5) | 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 | Yes (4191 ÷ 11 = 381) | 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 4191 a prime number?
No. 4191 = 3 × 11 × 127, so it is divisible by 3.
What are the factors of 4191?
1, 3, 11, 33, 127, 381, 1397, 4191.
What is 4191 in binary?
1000001011111 (hexadecimal 105F, octal 10137).
What is the square root of 4191?
About 64.7379.
Is 4191 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 4191?
It is a composite number with 8 divisors.