The number 16891
16891 is a composite number with 8 divisors. Its prime factorisation is 7 × 19 × 127. Divisors (8): 1, 7, 19, 127, 133, 889, 2413, 16891.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
16891 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
16891 is composite. Its prime factorisation is
- 3
The divisors add up to 20480; without 16891 itself that is 3589, so 16891 is deficient (3589 is less than 16891). Euler's totient φ(16891) = 13608 numbers up to 16891 share no factor with it.
- 4
The digits of 16891 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 159 steps to reach 1.
LaTeX source of the formulas on this page
\[ 16891 = 7 \times 19 \times 127 \]
16891 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 20480 |
| Euler totient φ(n) | 13608 |
| Square | 285305881 |
| Cube | 4819101635971 |
| Square root | 129.965380 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 159 |
| Scientific notation | 1.6891 × |
16891 in other forms
| Form | Value |
|---|---|
| In words | sixteen thousand eight hundred and ninety-one |
| Binary (base 2) | 100000111111011 |
| Octal (base 8) | 40773 |
| Hexadecimal (base 16) | 41FB |
| Base 3 | 212011121 |
| As time | 16891 seconds = 4 h 41 min 31 s |
Is 16891 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 | No (remainder 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (16891 ÷ 7 = 2413) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 16891 a prime number?
No. 16891 = 7 × 19 × 127, so it is divisible by 7.
What are the factors of 16891?
1, 7, 19, 127, 133, 889, 2413, 16891.
What is 16891 in binary?
100000111111011 (hexadecimal 41FB, octal 40773).
What is the square root of 16891?
About 129.9654.
Is 16891 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 16891?
It is a composite number with 8 divisors.