The number 15688
15688 is a composite number with 16 divisors. Its prime factorisation is × 37 × 53. Divisors (16): 1, 2, 4, 8, 37, 53, 74, 106, 148, 212, 296, 424, 1961, 3922, 7844, 15688.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 15688: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
15688 is composite. Its prime factorisation is
- 3
The divisors add up to 30780; without 15688 itself that is 15092, so 15688 is deficient (15092 is less than 15688). Euler's totient φ(15688) = 7488 numbers up to 15688 share no factor with it.
- 4
The digits of 15688 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 177 steps to reach 1.
LaTeX source of the formulas on this page
\[ 15688 = 2^{3} \times 37 \times 53 \]15688 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 30780 |
| Euler totient φ(n) | 7488 |
| Square | 246113344 |
| Cube | 3861026140672 |
| Square root | 125.251746 (= 2√3922) |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 177 |
| Scientific notation | 1.5688 × |
15688 in other forms
| Form | Value |
|---|---|
| In words | fifteen thousand six hundred and eighty-eight |
| Binary (base 2) | 11110101001000 |
| Octal (base 8) | 36510 |
| Hexadecimal (base 16) | 3D48 |
| Base 3 | 210112001 |
| As time | 15688 seconds = 4 h 21 min 28 s |
Is 15688 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (15688 ÷ 2 = 7844) | 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 (15688 ÷ 4 = 3922) | 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 1) | 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 (15688 ÷ 8 = 1961) | 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 2) | 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 15688 a prime number?
No. 15688 = × 37 × 53, so it is divisible by 2.
What are the factors of 15688?
1, 2, 4, 8, 37, 53, 74, 106, 148, 212, 296, 424, 1961, 3922, 7844, 15688.
What is 15688 in binary?
11110101001000 (hexadecimal 3D48, octal 36510).
What is the square root of 15688?
About 125.2517, exactly 2√3922.
Is 15688 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 15688?
15688 is a happy number: repeatedly adding the squares of its digits reaches 1.