The number 16385
16385 is a binary palindrome (100000000000001). Its prime factorisation is 5 × 29 × 113. Divisors (8): 1, 5, 29, 113, 145, 565, 3277, 16385.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 16385: a binary palindrome (100000000000001).
- 2
16385 is composite. Its prime factorisation is
- 3
The divisors add up to 20520; without 16385 itself that is 4135, so 16385 is deficient (4135 is less than 16385). Euler's totient φ(16385) = 12544 numbers up to 16385 share no factor with it.
- 4
The digits of 16385 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 53 steps to reach 1.
LaTeX source of the formulas on this page
\[ 16385 = 5 \times 29 \times 113 \]
16385 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 20520 |
| Euler totient φ(n) | 12544 |
| Square | 268468225 |
| Cube | 4398851866625 |
| Square root | 128.003906 |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 53 |
| Scientific notation | 1.6385 × |
16385 in other forms
| Form | Value |
|---|---|
| In words | sixteen thousand three hundred and eighty-five |
| Binary (base 2) | 100000000000001 |
| Octal (base 8) | 40001 |
| Hexadecimal (base 16) | 4001 |
| Base 3 | 211110212 |
| As time | 16385 seconds = 4 h 33 min 5 s |
Is 16385 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 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (16385 ÷ 5 = 3277) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 16385 a prime number?
No. 16385 = 5 × 29 × 113, so it is divisible by 5.
What are the factors of 16385?
1, 5, 29, 113, 145, 565, 3277, 16385.
What is 16385 in binary?
100000000000001 (hexadecimal 4001, octal 40001).
What is the square root of 16385?
About 128.0039.
Is 16385 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 16385?
16385 is a binary palindrome (100000000000001).