The number 31864
31864 is a composite number with 16 divisors. Its prime factorisation is × 7 × 569. Divisors (16): 1, 2, 4, 7, 8, 14, 28, 56, 569, 1138, 2276, 3983, 4552, 7966, 15932, 31864.
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How to work it out
- 1
31864 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31864 is composite. Its prime factorisation is
- 3
The divisors add up to 68400; without 31864 itself that is 36536, so 31864 is abundant (36536 is more than 31864). Euler's totient φ(31864) = 13632 numbers up to 31864 share no factor with it.
- 4
The digits of 31864 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 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31864 = 2^{3} \times 7 \times 569 \]31864 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 68400 |
| Euler totient φ(n) | 13632 |
| Square | 1015314496 |
| Cube | 32351981100544 |
| Square root | 178.504902 (= 2√7966) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.1864 × |
31864 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand eight hundred and sixty-four |
| Binary (base 2) | 111110001111000 |
| Octal (base 8) | 76170 |
| Hexadecimal (base 16) | 7C78 |
| Base 3 | 1121201011 |
| As time | 31864 seconds = 8 h 51 min 4 s |
Is 31864 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31864 ÷ 2 = 15932) | 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 (31864 ÷ 4 = 7966) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 | Yes (31864 ÷ 7 = 4552) | 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 (31864 ÷ 8 = 3983) | 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 4) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31864 a prime number?
No. 31864 = × 7 × 569, so it is divisible by 2.
What are the factors of 31864?
1, 2, 4, 7, 8, 14, 28, 56, 569, 1138, 2276, 3983, 4552, 7966, 15932, 31864.
What is 31864 in binary?
111110001111000 (hexadecimal 7C78, octal 76170).
What is the square root of 31864?
About 178.5049, exactly 2√7966.
Is 31864 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 31864?
It is a composite number with 16 divisors.