The number 31131
31131 is a composite number with 8 divisors. Its prime factorisation is × 1153. Divisors (8): 1, 3, 9, 27, 1153, 3459, 10377, 31131.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31131: a Harshad number: divisible by its digit sum 9.
- 2
31131 is composite. Its prime factorisation is
- 3
The divisors add up to 46160; without 31131 itself that is 15029, so 31131 is deficient (15029 is less than 31131). Euler's totient φ(31131) = 20736 numbers up to 31131 share no factor with it.
- 4
The digits of 31131 add up to 9, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 134 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31131 = 3^{3} \times 1153 \]31131 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 46160 |
| Euler totient φ(n) | 20736 |
| Square | 969139161 |
| Cube | 30170271221091 |
| Square root | 176.439791 (= 3√3459) |
| Digit sum / digital root | 9 / 9 |
| Collatz steps to 1 | 134 |
| Scientific notation | 3.1131 × |
31131 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand one hundred and thirty-one |
| Binary (base 2) | 111100110011011 |
| Octal (base 8) | 74633 |
| Hexadecimal (base 16) | 799B |
| Base 3 | 1120201000 |
| As time | 31131 seconds = 8 h 38 min 51 s |
Is 31131 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (31131 ÷ 3 = 10377) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | 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 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (31131 ÷ 9 = 3459) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31131 a prime number?
No. 31131 = × 1153, so it is divisible by 3.
What are the factors of 31131?
1, 3, 9, 27, 1153, 3459, 10377, 31131.
What is 31131 in binary?
111100110011011 (hexadecimal 799B, octal 74633).
What is the square root of 31131?
About 176.4398, exactly 3√3459.
Is 31131 divisible by 3?
Yes. Its digits add up to 9, a multiple of 3.
What is special about the number 31131?
31131 is a Harshad number: divisible by its digit sum 9.