The number 15808
15808 is a composite number with 28 divisors. Its prime factorisation is × 13 × 19. Divisors (28): 1, 2, 4, 8, 13, 16, 19, 26, 32, 38, 52, 64, 76, 104, 152, 208 … 15808.
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How to work it out
- 1
15808 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
15808 is composite. Its prime factorisation is
- 3
The divisors add up to 35560; without 15808 itself that is 19752, so 15808 is abundant (19752 is more than 15808). Euler's totient φ(15808) = 6912 numbers up to 15808 share no factor with it.
- 4
The digits of 15808 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 53 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15808 = 2^{6} \times 13 \times 19 \]15808 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 28 |
| Sum of divisors | 35560 |
| Euler totient φ(n) | 6912 |
| Square | 249892864 |
| Cube | 3950306394112 |
| Square root | 125.729869 (= 8√247) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 53 |
| Scientific notation | 1.5808 × |
15808 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand eight hundred and eight |
| Binary (base 2) | 11110111000000 |
| Octal (base 8) | 36700 |
| Hexadecimal (base 16) | 3DC0 |
| Base 3 | 210200111 |
| As time | 15808 seconds = 4 h 23 min 28 s |
Is 15808 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15808 ÷ 2 = 7904) | 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 (15808 ÷ 4 = 3952) | 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 2) | 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 (15808 ÷ 8 = 1976) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | 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 1) | 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 15808 a prime number?
No. 15808 = × 13 × 19, so it is divisible by 2.
What are the factors of 15808?
1, 2, 4, 8, 13, 16, 19, 26, 32, 38, 52, 64, 76, 104, 152, 208, 247, 304, 416, 494, 608, 832, 988, 1216, 1976, 3952, 7904, 15808.
What is 15808 in binary?
11110111000000 (hexadecimal 3DC0, octal 36700).
What is the square root of 15808?
About 125.7299, exactly 8√247.
Is 15808 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 15808?
It is a composite number with 28 divisors.