The number 15687
15687 is a composite number with 16 divisors. Its prime factorisation is × 7 × 83. Divisors (16): 1, 3, 7, 9, 21, 27, 63, 83, 189, 249, 581, 747, 1743, 2241, 5229, 15687.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 15687: a Harshad number: divisible by its digit sum 27.
- 2
15687 is composite. Its prime factorisation is
- 3
The divisors add up to 26880; without 15687 itself that is 11193, so 15687 is deficient (11193 is less than 15687). Euler's totient φ(15687) = 8856 numbers up to 15687 share no factor with it.
- 4
The digits of 15687 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 146 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15687 = 3^{3} \times 7 \times 83 \]15687 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 26880 |
| Euler totient φ(n) | 8856 |
| Square | 246081969 |
| Cube | 3860287847703 |
| Square root | 125.247754 (= 3√1743) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 146 |
| Scientific notation | 1.5687 × |
15687 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand six hundred and eighty-seven |
| Binary (base 2) | 11110101000111 |
| Octal (base 8) | 36507 |
| Hexadecimal (base 16) | 3D47 |
| Base 3 | 210112000 |
| As time | 15687 seconds = 4 h 21 min 27 s |
Is 15687 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 (15687 ÷ 3 = 5229) | 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 2) | 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 | Yes (15687 ÷ 7 = 2241) | 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 | Yes (15687 ÷ 9 = 1743) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 15687 a prime number?
No. 15687 = × 7 × 83, so it is divisible by 3.
What are the factors of 15687?
1, 3, 7, 9, 21, 27, 63, 83, 189, 249, 581, 747, 1743, 2241, 5229, 15687.
What is 15687 in binary?
11110101000111 (hexadecimal 3D47, octal 36507).
What is the square root of 15687?
About 125.2478, exactly 3√1743.
Is 15687 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 15687?
15687 is a Harshad number: divisible by its digit sum 27.