The number 31040
31040 is a composite number with 28 divisors. Its prime factorisation is × 5 × 97. Divisors (28): 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 97, 160, 194, 320 … 31040.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31040: a Harshad number: divisible by its digit sum 8.
- 2
31040 is composite. Its prime factorisation is
- 3
The divisors add up to 74676; without 31040 itself that is 43636, so 31040 is abundant (43636 is more than 31040). Euler's totient φ(31040) = 12288 numbers up to 31040 share no factor with it.
- 4
The digits of 31040 add up to 8, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 103 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31040 = 2^{6} \times 5 \times 97 \]31040 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 28 |
| Sum of divisors | 74676 |
| Euler totient φ(n) | 12288 |
| Square | 963481600 |
| Cube | 29906468864000 |
| Square root | 176.181724 (= 8√485) |
| Digit sum / digital root | 8 / 8 |
| Collatz steps to 1 | 103 |
| Scientific notation | 3.104 × |
31040 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand and forty |
| Binary (base 2) | 111100101000000 |
| Octal (base 8) | 74500 |
| Hexadecimal (base 16) | 7940 |
| Base 3 | 1120120122 |
| As time | 31040 seconds = 8 h 37 min 20 s |
Is 31040 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31040 ÷ 2 = 15520) | 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 (31040 ÷ 4 = 7760) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (31040 ÷ 5 = 6208) | 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 2) | 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 | Yes (31040 ÷ 8 = 3880) | 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 (31040 ÷ 10 = 3104) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31040 a prime number?
No. 31040 = × 5 × 97, so it is divisible by 2.
What are the factors of 31040?
1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 97, 160, 194, 320, 388, 485, 776, 970, 1552, 1940, 3104, 3880, 6208, 7760, 15520, 31040.
What is 31040 in binary?
111100101000000 (hexadecimal 7940, octal 74500).
What is the square root of 31040?
About 176.1817, exactly 8√485.
Is 31040 divisible by 3?
No. Its digits add up to 8, which is not a multiple of 3.
What is special about the number 31040?
31040 is a Harshad number: divisible by its digit sum 8.