The number 31816
31816 is a composite number with 16 divisors. Its prime factorisation is × 41 × 97. Divisors (16): 1, 2, 4, 8, 41, 82, 97, 164, 194, 328, 388, 776, 3977, 7954, 15908, 31816.
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How to work it out
- 1
31816 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31816 is composite. Its prime factorisation is
- 3
The divisors add up to 61740; without 31816 itself that is 29924, so 31816 is deficient (29924 is less than 31816). Euler's totient φ(31816) = 15360 numbers up to 31816 share no factor with it.
- 4
The digits of 31816 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 147 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31816 = 2^{3} \times 41 \times 97 \]31816 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 61740 |
| Euler totient φ(n) | 15360 |
| Square | 1012257856 |
| Cube | 32205995946496 |
| Square root | 178.370401 (= 2√7954) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 147 |
| Scientific notation | 3.1816 × |
31816 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand eight hundred and sixteen |
| Binary (base 2) | 111110001001000 |
| Octal (base 8) | 76110 |
| Hexadecimal (base 16) | 7C48 |
| Base 3 | 1121122101 |
| As time | 31816 seconds = 8 h 50 min 16 s |
Is 31816 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31816 ÷ 2 = 15908) | 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 (31816 ÷ 4 = 7954) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | 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 (31816 ÷ 8 = 3977) | 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 6) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 31816 a prime number?
No. 31816 = × 41 × 97, so it is divisible by 2.
What are the factors of 31816?
1, 2, 4, 8, 41, 82, 97, 164, 194, 328, 388, 776, 3977, 7954, 15908, 31816.
What is 31816 in binary?
111110001001000 (hexadecimal 7C48, octal 76110).
What is the square root of 31816?
About 178.3704, exactly 2√7954.
Is 31816 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 31816?
It is a composite number with 16 divisors.