The number 31812
31812 is a composite number with 24 divisors. Its prime factorisation is × 3 × 11 × 241. Divisors (24): 1, 2, 3, 4, 6, 11, 12, 22, 33, 44, 66, 132, 241, 482, 723, 964 … 31812.
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How to work it out
- 1
What is special about 31812: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
31812 is composite. Its prime factorisation is
- 3
The divisors add up to 81312; without 31812 itself that is 49500, so 31812 is abundant (49500 is more than 31812). Euler's totient φ(31812) = 9600 numbers up to 31812 share no factor with it.
- 4
The digits of 31812 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 98 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31812 = 2^{2} \times 3 \times 11 \times 241 \]31812 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 81312 |
| Euler totient φ(n) | 9600 |
| Square | 1012003344 |
| Cube | 32193850379328 |
| Square root | 178.359188 (= 2√7953) |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 98 |
| Scientific notation | 3.1812 × |
31812 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand eight hundred and twelve |
| Binary (base 2) | 111110001000100 |
| Octal (base 8) | 76104 |
| Hexadecimal (base 16) | 7C44 |
| Base 3 | 1121122020 |
| As time | 31812 seconds = 8 h 50 min 12 s |
Is 31812 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31812 ÷ 2 = 15906) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (31812 ÷ 3 = 10604) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (31812 ÷ 4 = 7953) | 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 | Yes (31812 ÷ 6 = 5302) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (31812 ÷ 11 = 2892) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (31812 ÷ 12 = 2651) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31812 a prime number?
No. 31812 = × 3 × 11 × 241, so it is divisible by 2.
What are the factors of 31812?
1, 2, 3, 4, 6, 11, 12, 22, 33, 44, 66, 132, 241, 482, 723, 964, 1446, 2651, 2892, 5302, 7953, 10604, 15906, 31812.
What is 31812 in binary?
111110001000100 (hexadecimal 7C44, octal 76104).
What is the square root of 31812?
About 178.3592, exactly 2√7953.
Is 31812 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 31812?
31812 is a happy number: repeatedly adding the squares of its digits reaches 1.