The number 31942
31942 is a composite number with 4 divisors. Its prime factorisation is 2 × 15971. Divisors (4): 1, 2, 15971, 31942.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31942: a semiprime: 2 × 15971, the product of two primes.
- 2
31942 is composite. Its prime factorisation is
- 3
The divisors add up to 47916; without 31942 itself that is 15974, so 31942 is deficient (15974 is less than 31942). Euler's totient φ(31942) = 15970 numbers up to 31942 share no factor with it.
- 4
The digits of 31942 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31942 = 2 \times 15971 \]
31942 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 47916 |
| Euler totient φ(n) | 15970 |
| Square | 1020291364 |
| Cube | 32590146748888 |
| Square root | 178.723250 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.1942 × |
31942 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and forty-two |
| Binary (base 2) | 111110011000110 |
| Octal (base 8) | 76306 |
| Hexadecimal (base 16) | 7CC6 |
| Base 3 | 1121211001 |
| As time | 31942 seconds = 8 h 52 min 22 s |
Is 31942 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31942 ÷ 2 = 15971) | 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 2) | 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 4) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31942 a prime number?
No. 31942 = 2 × 15971, so it is divisible by 2.
What are the factors of 31942?
1, 2, 15971, 31942.
What is 31942 in binary?
111110011000110 (hexadecimal 7CC6, octal 76306).
What is the square root of 31942?
About 178.7232.
Is 31942 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 31942?
31942 is a semiprime: 2 × 15971, the product of two primes.