The number 31688
31688 is a composite number with 16 divisors. Its prime factorisation is × 17 × 233. Divisors (16): 1, 2, 4, 8, 17, 34, 68, 136, 233, 466, 932, 1864, 3961, 7922, 15844, 31688.
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How to work it out
- 1
31688 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31688 is composite. Its prime factorisation is
- 3
The divisors add up to 63180; without 31688 itself that is 31492, so 31688 is deficient (31492 is less than 31688). Euler's totient φ(31688) = 14848 numbers up to 31688 share no factor with it.
- 4
The digits of 31688 add up to 26, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31688 = 2^{3} \times 17 \times 233 \]31688 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 63180 |
| Euler totient φ(n) | 14848 |
| Square | 1004129344 |
| Cube | 31818850652672 |
| Square root | 178.011236 (= 2√7922) |
| Digit sum / digital root | 26 / 8 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.1688 × |
31688 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand six hundred and eighty-eight |
| Binary (base 2) | 111101111001000 |
| Octal (base 8) | 75710 |
| Hexadecimal (base 16) | 7BC8 |
| Base 3 | 1121110122 |
| As time | 31688 seconds = 8 h 48 min 8 s |
Is 31688 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31688 ÷ 2 = 15844) | 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 | Yes (31688 ÷ 4 = 7922) | 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 2) | 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 (31688 ÷ 8 = 3961) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | 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 8) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31688 a prime number?
No. 31688 = × 17 × 233, so it is divisible by 2.
What are the factors of 31688?
1, 2, 4, 8, 17, 34, 68, 136, 233, 466, 932, 1864, 3961, 7922, 15844, 31688.
What is 31688 in binary?
111101111001000 (hexadecimal 7BC8, octal 75710).
What is the square root of 31688?
About 178.0112, exactly 2√7922.
Is 31688 divisible by 3?
No. Its digits add up to 26, which is not a multiple of 3.
What is special about the number 31688?
It is a composite number with 16 divisors.