The number 56991
56991 is a composite number with 12 divisors. Its prime factorisation is 3 × × 157. Divisors (12): 1, 3, 11, 33, 121, 157, 363, 471, 1727, 5181, 18997, 56991.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
56991 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
56991 is composite. Its prime factorisation is
- 3
The divisors add up to 84056; without 56991 itself that is 27065, so 56991 is deficient (27065 is less than 56991). Euler's totient φ(56991) = 34320 numbers up to 56991 share no factor with it.
- 4
The digits of 56991 add up to 30, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 122 steps to reach 1.
LaTeX source of the formulas on this page
\[ 56991 = 3 \times 11^{2} \times 157 \]56991 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 84056 |
| Euler totient φ(n) | 34320 |
| Square | 3247974081 |
| Cube | 185105290850271 |
| Square root | 238.727879 (= 11√471) |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 122 |
| Scientific notation | 5.6991 × |
56991 in other forms
| Form | Value |
|---|---|
| In words | fifty-six thousand nine hundred and ninety-one |
| Binary (base 2) | 1101111010011111 |
| Octal (base 8) | 157237 |
| Hexadecimal (base 16) | DE9F |
| Base 3 | 2220011210 |
| As time | 56991 seconds = 15 h 49 min 51 s |
Is 56991 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 (56991 ÷ 3 = 18997) | 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 4) | 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 3) | 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 (56991 ÷ 11 = 5181) | 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 56991 a prime number?
No. 56991 = 3 × × 157, so it is divisible by 3.
What are the factors of 56991?
1, 3, 11, 33, 121, 157, 363, 471, 1727, 5181, 18997, 56991.
What is 56991 in binary?
1101111010011111 (hexadecimal DE9F, octal 157237).
What is the square root of 56991?
About 238.7279, exactly 11√471.
Is 56991 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 56991?
It is a composite number with 12 divisors.