The number 31836
31836 is a composite number with 24 divisors. Its prime factorisation is × 3 × 7 × 379. Divisors (24): 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84, 379, 758, 1137, 1516 … 31836.
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How to work it out
- 1
What is special about 31836: a Harshad number: divisible by its digit sum 21.
- 2
31836 is composite. Its prime factorisation is
- 3
The divisors add up to 85120; without 31836 itself that is 53284, so 31836 is abundant (53284 is more than 31836). Euler's totient φ(31836) = 9072 numbers up to 31836 share no factor with it.
- 4
The digits of 31836 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 98 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31836 = 2^{2} \times 3 \times 7 \times 379 \]31836 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 85120 |
| Euler totient φ(n) | 9072 |
| Square | 1013530896 |
| Cube | 32266769605056 |
| Square root | 178.426455 (= 2√7959) |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 98 |
| Scientific notation | 3.1836 × |
31836 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand eight hundred and thirty-six |
| Binary (base 2) | 111110001011100 |
| Octal (base 8) | 76134 |
| Hexadecimal (base 16) | 7C5C |
| Base 3 | 1121200010 |
| As time | 31836 seconds = 8 h 50 min 36 s |
Is 31836 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31836 ÷ 2 = 15918) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (31836 ÷ 3 = 10612) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (31836 ÷ 4 = 7959) | 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 | Yes (31836 ÷ 6 = 5306) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (31836 ÷ 7 = 4548) | 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 3) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (31836 ÷ 12 = 2653) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31836 a prime number?
No. 31836 = × 3 × 7 × 379, so it is divisible by 2.
What are the factors of 31836?
1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84, 379, 758, 1137, 1516, 2274, 2653, 4548, 5306, 7959, 10612, 15918, 31836.
What is 31836 in binary?
111110001011100 (hexadecimal 7C5C, octal 76134).
What is the square root of 31836?
About 178.4265, exactly 2√7959.
Is 31836 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 31836?
31836 is a Harshad number: divisible by its digit sum 21.