The number 31457
31457 is a composite number with 4 divisors. Its prime factorisation is 83 × 379. Divisors (4): 1, 83, 379, 31457.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31457: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 83 × 379, the product of two primes.
- 2
31457 is composite. Its prime factorisation is
- 3
The divisors add up to 31920; without 31457 itself that is 463, so 31457 is deficient (463 is less than 31457). Euler's totient φ(31457) = 30996 numbers up to 31457 share no factor with it.
- 4
The digits of 31457 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 85 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31457 = 83 \times 379 \]
31457 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 31920 |
| Euler totient φ(n) | 30996 |
| Square | 989542849 |
| Cube | 31128049400993 |
| Square root | 177.361213 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 85 |
| Scientific notation | 3.1457 × |
31457 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand four hundred and fifty-seven |
| Binary (base 2) | 111101011100001 |
| Octal (base 8) | 75341 |
| Hexadecimal (base 16) | 7AE1 |
| Base 3 | 1121011002 |
| As time | 31457 seconds = 8 h 44 min 17 s |
Is 31457 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 2) | 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 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 31457 a prime number?
No. 31457 = 83 × 379, so it is divisible by 83.
What are the factors of 31457?
1, 83, 379, 31457.
What is 31457 in binary?
111101011100001 (hexadecimal 7AE1, octal 75341).
What is the square root of 31457?
About 177.3612.
Is 31457 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 31457?
31457 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 83 × 379, the product of two primes.