The number 31814
31814 is a composite number with 4 divisors. Its prime factorisation is 2 × 15907. Divisors (4): 1, 2, 15907, 31814.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31814: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 15907, the product of two primes.
- 2
31814 is composite. Its prime factorisation is
- 3
The divisors add up to 47724; without 31814 itself that is 15910, so 31814 is deficient (15910 is less than 31814). Euler's totient φ(31814) = 15906 numbers up to 31814 share no factor with it.
- 4
The digits of 31814 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 98 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31814 = 2 \times 15907 \]
31814 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 47724 |
| Euler totient φ(n) | 15906 |
| Square | 1012130596 |
| Cube | 32199922781144 |
| Square root | 178.364795 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 98 |
| Scientific notation | 3.1814 × |
31814 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand eight hundred and fourteen |
| Binary (base 2) | 111110001000110 |
| Octal (base 8) | 76106 |
| Hexadecimal (base 16) | 7C46 |
| Base 3 | 1121122022 |
| As time | 31814 seconds = 8 h 50 min 14 s |
Is 31814 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31814 ÷ 2 = 15907) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | 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 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31814 a prime number?
No. 31814 = 2 × 15907, so it is divisible by 2.
What are the factors of 31814?
1, 2, 15907, 31814.
What is 31814 in binary?
111110001000110 (hexadecimal 7C46, octal 76106).
What is the square root of 31814?
About 178.3648.
Is 31814 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 31814?
31814 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 15907, the product of two primes.