The number 31660
31660 is a composite number with 12 divisors. Its prime factorisation is × 5 × 1583. Divisors (12): 1, 2, 4, 5, 10, 20, 1583, 3166, 6332, 7915, 15830, 31660.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31660: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
31660 is composite. Its prime factorisation is
- 3
The divisors add up to 66528; without 31660 itself that is 34868, so 31660 is abundant (34868 is more than 31660). Euler's totient φ(31660) = 12656 numbers up to 31660 share no factor with it.
- 4
The digits of 31660 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 103 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31660 = 2^{2} \times 5 \times 1583 \]31660 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 66528 |
| Euler totient φ(n) | 12656 |
| Square | 1002355600 |
| Cube | 31734578296000 |
| Square root | 177.932571 (= 2√7915) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 103 |
| Scientific notation | 3.166 × |
31660 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand six hundred and sixty |
| Binary (base 2) | 111101110101100 |
| Octal (base 8) | 75654 |
| Hexadecimal (base 16) | 7BAC |
| Base 3 | 1121102121 |
| As time | 31660 seconds = 8 h 47 min 40 s |
Is 31660 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31660 ÷ 2 = 15830) | 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 | Yes (31660 ÷ 4 = 7915) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (31660 ÷ 5 = 6332) | 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 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 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (31660 ÷ 10 = 3166) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31660 a prime number?
No. 31660 = × 5 × 1583, so it is divisible by 2.
What are the factors of 31660?
1, 2, 4, 5, 10, 20, 1583, 3166, 6332, 7915, 15830, 31660.
What is 31660 in binary?
111101110101100 (hexadecimal 7BAC, octal 75654).
What is the square root of 31660?
About 177.9326, exactly 2√7915.
Is 31660 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 31660?
31660 is a happy number: repeatedly adding the squares of its digits reaches 1.