The number 31828
31828 is a composite number with 12 divisors. Its prime factorisation is × 73 × 109. Divisors (12): 1, 2, 4, 73, 109, 146, 218, 292, 436, 7957, 15914, 31828.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
31828 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31828 is composite. Its prime factorisation is
- 3
The divisors add up to 56980; without 31828 itself that is 25152, so 31828 is deficient (25152 is less than 31828). Euler's totient φ(31828) = 15552 numbers up to 31828 share no factor with it.
- 4
The digits of 31828 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 28 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31828 = 2^{2} \times 73 \times 109 \]31828 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 56980 |
| Euler totient φ(n) | 15552 |
| Square | 1013021584 |
| Cube | 32242450975552 |
| Square root | 178.404036 (= 2√7957) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 28 |
| Scientific notation | 3.1828 × |
31828 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand eight hundred and twenty-eight |
| Binary (base 2) | 111110001010100 |
| Octal (base 8) | 76124 |
| Hexadecimal (base 16) | 7C54 |
| Base 3 | 1121122211 |
| As time | 31828 seconds = 8 h 50 min 28 s |
Is 31828 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31828 ÷ 2 = 15914) | 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 (31828 ÷ 4 = 7957) | 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 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 | No (remainder 4) | 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 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | 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 31828 a prime number?
No. 31828 = × 73 × 109, so it is divisible by 2.
What are the factors of 31828?
1, 2, 4, 73, 109, 146, 218, 292, 436, 7957, 15914, 31828.
What is 31828 in binary?
111110001010100 (hexadecimal 7C54, octal 76124).
What is the square root of 31828?
About 178.4040, exactly 2√7957.
Is 31828 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 31828?
It is a composite number with 12 divisors.