The number 31356
31356 is a composite number with 36 divisors. Its prime factorisation is × × 13 × 67. Divisors (36): 1, 2, 3, 4, 6, 9, 12, 13, 18, 26, 36, 39, 52, 67, 78, 117 … 31356.
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How to work it out
- 1
What is special about 31356: a Harshad number: divisible by its digit sum 18.
- 2
31356 is composite. Its prime factorisation is
- 3
The divisors add up to 86632; without 31356 itself that is 55276, so 31356 is abundant (55276 is more than 31356). Euler's totient φ(31356) = 9504 numbers up to 31356 share no factor with it.
- 4
The digits of 31356 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 85 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31356 = 2^{2} \times 3^{2} \times 13 \times 67 \]31356 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 36 |
| Sum of divisors | 86632 |
| Euler totient φ(n) | 9504 |
| Square | 983198736 |
| Cube | 30829179566016 |
| Square root | 177.076255 (= 6√871) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 85 |
| Scientific notation | 3.1356 × |
31356 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand three hundred and fifty-six |
| Binary (base 2) | 111101001111100 |
| Octal (base 8) | 75174 |
| Hexadecimal (base 16) | 7A7C |
| Base 3 | 1121000100 |
| As time | 31356 seconds = 8 h 42 min 36 s |
Is 31356 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31356 ÷ 2 = 15678) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (31356 ÷ 3 = 10452) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (31356 ÷ 4 = 7839) | 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 (31356 ÷ 6 = 5226) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 | Yes (31356 ÷ 9 = 3484) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (31356 ÷ 12 = 2613) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31356 a prime number?
No. 31356 = × × 13 × 67, so it is divisible by 2.
What are the factors of 31356?
1, 2, 3, 4, 6, 9, 12, 13, 18, 26, 36, 39, 52, 67, 78, 117, 134, 156, 201, 234, 268, 402, 468, 603, 804, 871, 1206, 1742, 2412, 2613, 3484, 5226, 7839, 10452, 15678, 31356.
What is 31356 in binary?
111101001111100 (hexadecimal 7A7C, octal 75174).
What is the square root of 31356?
About 177.0763, exactly 6√871.
Is 31356 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 31356?
31356 is a Harshad number: divisible by its digit sum 18.