The number 31471
31471 is a composite number with 4 divisors. Its prime factorisation is 11 × 2861. Divisors (4): 1, 11, 2861, 31471.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31471: a semiprime: 11 × 2861, the product of two primes.
- 2
31471 is composite. Its prime factorisation is
- 3
The divisors add up to 34344; without 31471 itself that is 2873, so 31471 is deficient (2873 is less than 31471). Euler's totient φ(31471) = 28600 numbers up to 31471 share no factor with it.
- 4
The digits of 31471 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 85 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31471 = 11 \times 2861 \]
31471 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 34344 |
| Euler totient φ(n) | 28600 |
| Square | 990423841 |
| Cube | 31169628700111 |
| Square root | 177.400676 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 85 |
| Scientific notation | 3.1471 × |
31471 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand four hundred and seventy-one |
| Binary (base 2) | 111101011101111 |
| Octal (base 8) | 75357 |
| Hexadecimal (base 16) | 7AEF |
| Base 3 | 1121011121 |
| As time | 31471 seconds = 8 h 44 min 31 s |
Is 31471 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 6) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 | Yes (31471 ÷ 11 = 2861) | 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 31471 a prime number?
No. 31471 = 11 × 2861, so it is divisible by 11.
What are the factors of 31471?
1, 11, 2861, 31471.
What is 31471 in binary?
111101011101111 (hexadecimal 7AEF, octal 75357).
What is the square root of 31471?
About 177.4007.
Is 31471 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 31471?
31471 is a semiprime: 11 × 2861, the product of two primes.