The number 31361
31361 is a composite number with 4 divisors. Its prime factorisation is 11 × 2851. Divisors (4): 1, 11, 2851, 31361.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31361: a semiprime: 11 × 2851, the product of two primes.
- 2
31361 is composite. Its prime factorisation is
- 3
The divisors add up to 34224; without 31361 itself that is 2863, so 31361 is deficient (2863 is less than 31361). Euler's totient φ(31361) = 28500 numbers up to 31361 share no factor with it.
- 4
The digits of 31361 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 147 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31361 = 11 \times 2851 \]
31361 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 34224 |
| Euler totient φ(n) | 28500 |
| Square | 983512321 |
| Cube | 30843929898881 |
| Square root | 177.090372 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 147 |
| Scientific notation | 3.1361 × |
31361 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand three hundred and sixty-one |
| Binary (base 2) | 111101010000001 |
| Octal (base 8) | 75201 |
| Hexadecimal (base 16) | 7A81 |
| Base 3 | 1121000112 |
| As time | 31361 seconds = 8 h 42 min 41 s |
Is 31361 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 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | 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 (31361 ÷ 11 = 2851) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31361 a prime number?
No. 31361 = 11 × 2851, so it is divisible by 11.
What are the factors of 31361?
1, 11, 2851, 31361.
What is 31361 in binary?
111101010000001 (hexadecimal 7A81, octal 75201).
What is the square root of 31361?
About 177.0904.
Is 31361 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 31361?
31361 is a semiprime: 11 × 2851, the product of two primes.