The number 35991
35991 is a composite number with 16 divisors. Its prime factorisation is × 31 × 43. Divisors (16): 1, 3, 9, 27, 31, 43, 93, 129, 279, 387, 837, 1161, 1333, 3999, 11997, 35991.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 35991: a Harshad number: divisible by its digit sum 27.
- 2
35991 is composite. Its prime factorisation is
- 3
The divisors add up to 56320; without 35991 itself that is 20329, so 35991 is deficient (20329 is less than 35991). Euler's totient φ(35991) = 22680 numbers up to 35991 share no factor with it.
- 4
The digits of 35991 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 49 steps to reach 1.
LaTeX source of the formulas on this page
\[ 35991 = 3^{3} \times 31 \times 43 \]35991 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 56320 |
| Euler totient φ(n) | 22680 |
| Square | 1295352081 |
| Cube | 46621016747271 |
| Square root | 189.712941 (= 3√3999) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 49 |
| Scientific notation | 3.5991 × |
35991 in other forms
| Form | Value |
|---|---|
| In words | thirty-five thousand nine hundred and ninety-one |
| Binary (base 2) | 1000110010010111 |
| Octal (base 8) | 106227 |
| Hexadecimal (base 16) | 8C97 |
| Base 3 | 1211101000 |
| As time | 35991 seconds = 9 h 59 min 51 s |
Is 35991 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 (35991 ÷ 3 = 11997) | 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 | Yes (35991 ÷ 9 = 3999) | 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 10) | 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 35991 a prime number?
No. 35991 = × 31 × 43, so it is divisible by 3.
What are the factors of 35991?
1, 3, 9, 27, 31, 43, 93, 129, 279, 387, 837, 1161, 1333, 3999, 11997, 35991.
What is 35991 in binary?
1000110010010111 (hexadecimal 8C97, octal 106227).
What is the square root of 35991?
About 189.7129, exactly 3√3999.
Is 35991 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 35991?
35991 is a Harshad number: divisible by its digit sum 27.