The number 29991
29991 is a composite number with 8 divisors. Its prime factorisation is 3 × 13 × 769. Divisors (8): 1, 3, 13, 39, 769, 2307, 9997, 29991.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
29991 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
29991 is composite. Its prime factorisation is
- 3
The divisors add up to 43120; without 29991 itself that is 13129, so 29991 is deficient (13129 is less than 29991). Euler's totient φ(29991) = 18432 numbers up to 29991 share no factor with it.
- 4
The digits of 29991 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 165 steps to reach 1.
LaTeX source of the formulas on this page
\[ 29991 = 3 \times 13 \times 769 \]
29991 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 43120 |
| Euler totient φ(n) | 18432 |
| Square | 899460081 |
| Cube | 26975707289271 |
| Square root | 173.179098 |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 165 |
| Scientific notation | 2.9991 × |
29991 in other forms
| Form | Value |
|---|---|
| In words | twenty-nine thousand nine hundred and ninety-one |
| Binary (base 2) | 111010100100111 |
| Octal (base 8) | 72447 |
| Hexadecimal (base 16) | 7527 |
| Base 3 | 1112010210 |
| As time | 29991 seconds = 8 h 19 min 51 s |
Is 29991 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 (29991 ÷ 3 = 9997) | 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 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 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 | No (remainder 5) | 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 29991 a prime number?
No. 29991 = 3 × 13 × 769, so it is divisible by 3.
What are the factors of 29991?
1, 3, 13, 39, 769, 2307, 9997, 29991.
What is 29991 in binary?
111010100100111 (hexadecimal 7527, octal 72447).
What is the square root of 29991?
About 173.1791.
Is 29991 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 29991?
It is a composite number with 8 divisors.