The number 39808
39808 is a composite number with 16 divisors. Its prime factorisation is × 311. Divisors (16): 1, 2, 4, 8, 16, 32, 64, 128, 311, 622, 1244, 2488, 4976, 9952, 19904, 39808.
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How to work it out
- 1
39808 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
39808 is composite. Its prime factorisation is
- 3
The divisors add up to 79560; without 39808 itself that is 39752, so 39808 is deficient (39752 is less than 39808). Euler's totient φ(39808) = 19840 numbers up to 39808 share no factor with it.
- 4
The digits of 39808 add up to 28, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 93 steps to reach 1.
LaTeX source of the formulas on this page
\[ 39808 = 2^{7} \times 311 \]39808 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 79560 |
| Euler totient φ(n) | 19840 |
| Square | 1584676864 |
| Cube | 63082816602112 |
| Square root | 199.519423 (= 8√622) |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 93 |
| Scientific notation | 3.9808 × |
39808 in other forms
| Form | Value |
|---|---|
| In words | thirty-nine thousand eight hundred and eight |
| Binary (base 2) | 1001101110000000 |
| Octal (base 8) | 115600 |
| Hexadecimal (base 16) | 9B80 |
| Base 3 | 2000121101 |
| As time | 39808 seconds = 11 h 3 min 28 s |
Is 39808 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (39808 ÷ 2 = 19904) | 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 | Yes (39808 ÷ 4 = 9952) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 | Yes (39808 ÷ 8 = 4976) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 39808 a prime number?
No. 39808 = × 311, so it is divisible by 2.
What are the factors of 39808?
1, 2, 4, 8, 16, 32, 64, 128, 311, 622, 1244, 2488, 4976, 9952, 19904, 39808.
What is 39808 in binary?
1001101110000000 (hexadecimal 9B80, octal 115600).
What is the square root of 39808?
About 199.5194, exactly 8√622.
Is 39808 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 39808?
It is a composite number with 16 divisors.