The number 31940
31940 is a composite number with 12 divisors. Its prime factorisation is × 5 × 1597. Divisors (12): 1, 2, 4, 5, 10, 20, 1597, 3194, 6388, 7985, 15970, 31940.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
31940 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
31940 is composite. Its prime factorisation is
- 3
The divisors add up to 67116; without 31940 itself that is 35176, so 31940 is abundant (35176 is more than 31940). Euler's totient φ(31940) = 12768 numbers up to 31940 share no factor with it.
- 4
The digits of 31940 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 54 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31940 = 2^{2} \times 5 \times 1597 \]31940 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 67116 |
| Euler totient φ(n) | 12768 |
| Square | 1020163600 |
| Cube | 32584025384000 |
| Square root | 178.717654 (= 2√7985) |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 54 |
| Scientific notation | 3.194 × |
31940 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand nine hundred and forty |
| Binary (base 2) | 111110011000100 |
| Octal (base 8) | 76304 |
| Hexadecimal (base 16) | 7CC4 |
| Base 3 | 1121210222 |
| As time | 31940 seconds = 8 h 52 min 20 s |
Is 31940 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31940 ÷ 2 = 15970) | 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 | Yes (31940 ÷ 4 = 7985) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (31940 ÷ 5 = 6388) | 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 4) | 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 | Yes (31940 ÷ 10 = 3194) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31940 a prime number?
No. 31940 = × 5 × 1597, so it is divisible by 2.
What are the factors of 31940?
1, 2, 4, 5, 10, 20, 1597, 3194, 6388, 7985, 15970, 31940.
What is 31940 in binary?
111110011000100 (hexadecimal 7CC4, octal 76304).
What is the square root of 31940?
About 178.7177, exactly 2√7985.
Is 31940 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 31940?
It is a composite number with 12 divisors.