The number 31730
31730 is a composite number with 16 divisors. Its prime factorisation is 2 × 5 × 19 × 167. Divisors (16): 1, 2, 5, 10, 19, 38, 95, 167, 190, 334, 835, 1670, 3173, 6346, 15865, 31730.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31730: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
31730 is composite. Its prime factorisation is
- 3
The divisors add up to 60480; without 31730 itself that is 28750, so 31730 is deficient (28750 is less than 31730). Euler's totient φ(31730) = 11952 numbers up to 31730 share no factor with it.
- 4
The digits of 31730 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 147 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31730 = 2 \times 5 \times 19 \times 167 \]
31730 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 60480 |
| Euler totient φ(n) | 11952 |
| Square | 1006792900 |
| Cube | 31945538717000 |
| Square root | 178.129167 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 147 |
| Scientific notation | 3.173 × |
31730 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand seven hundred and thirty |
| Binary (base 2) | 111101111110010 |
| Octal (base 8) | 75762 |
| Hexadecimal (base 16) | 7BF2 |
| Base 3 | 1121112012 |
| As time | 31730 seconds = 8 h 48 min 50 s |
Is 31730 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (31730 ÷ 2 = 15865) | 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 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (31730 ÷ 5 = 6346) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (31730 ÷ 10 = 3173) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31730 a prime number?
No. 31730 = 2 × 5 × 19 × 167, so it is divisible by 2.
What are the factors of 31730?
1, 2, 5, 10, 19, 38, 95, 167, 190, 334, 835, 1670, 3173, 6346, 15865, 31730.
What is 31730 in binary?
111101111110010 (hexadecimal 7BF2, octal 75762).
What is the square root of 31730?
About 178.1292.
Is 31730 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 31730?
31730 is a happy number: repeatedly adding the squares of its digits reaches 1.