The number 8131
8131 is a composite number with 4 divisors. Its prime factorisation is 47 × 173. Divisors (4): 1, 47, 173, 8131.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 8131: a semiprime: 47 × 173, the product of two primes.
- 2
8131 is composite. Its prime factorisation is
- 3
The divisors add up to 8352; without 8131 itself that is 221, so 8131 is deficient (221 is less than 8131). Euler's totient φ(8131) = 7912 numbers up to 8131 share no factor with it.
- 4
The digits of 8131 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 127 steps to reach 1.
LaTeX source of the formulas on this page
\[ 8131 = 47 \times 173 \]
8131 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 8352 |
| Euler totient φ(n) | 7912 |
| Square | 66113161 |
| Cube | 537566112091 |
| Square root | 90.172058 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 127 |
| Scientific notation | 8.131 × |
8131 in other forms
| Form | Value |
|---|---|
| In words | eight thousand one hundred and thirty-one |
| Binary (base 2) | 1111111000011 |
| Octal (base 8) | 17703 |
| Hexadecimal (base 16) | 1FC3 |
| Base 3 | 102011011 |
| As time | 8131 seconds = 2 h 15 min 31 s |
Is 8131 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 | No (remainder 1) | 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 1) | 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 | No (remainder 3) | 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 1) | 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 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 8131 a prime number?
No. 8131 = 47 × 173, so it is divisible by 47.
What are the factors of 8131?
1, 47, 173, 8131.
What is 8131 in binary?
1111111000011 (hexadecimal 1FC3, octal 17703).
What is the square root of 8131?
About 90.1721.
Is 8131 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 8131?
8131 is a semiprime: 47 × 173, the product of two primes.