The number 31392
31392 is a composite number with 36 divisors. Its prime factorisation is × × 109. Divisors (36): 1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 32, 36, 48, 72, 96 … 31392.
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How to work it out
- 1
What is special about 31392: a Harshad number: divisible by its digit sum 18.
- 2
31392 is composite. Its prime factorisation is
- 3
The divisors add up to 90090; without 31392 itself that is 58698, so 31392 is abundant (58698 is more than 31392). Euler's totient φ(31392) = 10368 numbers up to 31392 share no factor with it.
- 4
The digits of 31392 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 28 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31392 = 2^{5} \times 3^{2} \times 109 \]31392 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 36 |
| Sum of divisors | 90090 |
| Euler totient φ(n) | 10368 |
| Square | 985457664 |
| Cube | 30935486988288 |
| Square root | 177.177877 (= 12√218) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 28 |
| Scientific notation | 3.1392 × |
31392 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand three hundred and ninety-two |
| Binary (base 2) | 111101010100000 |
| Octal (base 8) | 75240 |
| Hexadecimal (base 16) | 7AA0 |
| Base 3 | 1121001200 |
| As time | 31392 seconds = 8 h 43 min 12 s |
Is 31392 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31392 ÷ 2 = 15696) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (31392 ÷ 3 = 10464) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (31392 ÷ 4 = 7848) | 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 (31392 ÷ 6 = 5232) | 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 | Yes (31392 ÷ 8 = 3924) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (31392 ÷ 9 = 3488) | 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 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (31392 ÷ 12 = 2616) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31392 a prime number?
No. 31392 = × × 109, so it is divisible by 2.
What are the factors of 31392?
1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 24, 32, 36, 48, 72, 96, 109, 144, 218, 288, 327, 436, 654, 872, 981, 1308, 1744, 1962, 2616, 3488, 3924, 5232, 7848, 10464, 15696, 31392.
What is 31392 in binary?
111101010100000 (hexadecimal 7AA0, octal 75240).
What is the square root of 31392?
About 177.1779, exactly 12√218.
Is 31392 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 31392?
31392 is a Harshad number: divisible by its digit sum 18.