The number 31825
31825 is a composite number with 12 divisors. Its prime factorisation is × 19 × 67. Divisors (12): 1, 5, 19, 25, 67, 95, 335, 475, 1273, 1675, 6365, 31825.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 31825: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 19.
- 2
31825 is composite. Its prime factorisation is
- 3
The divisors add up to 42160; without 31825 itself that is 10335, so 31825 is deficient (10335 is less than 31825). Euler's totient φ(31825) = 23760 numbers up to 31825 share no factor with it.
- 4
The digits of 31825 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 147 steps to reach 1.
LaTeX source of the formulas on this page
\[ 31825 = 5^{2} \times 19 \times 67 \]31825 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 42160 |
| Euler totient φ(n) | 23760 |
| Square | 1012830625 |
| Cube | 32233334640625 |
| Square root | 178.395628 (= 5√1273) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 147 |
| Scientific notation | 3.1825 × |
31825 in other forms
| Form | Value |
|---|---|
| In words | thirty-one thousand eight hundred and twenty-five |
| Binary (base 2) | 111110001010001 |
| Octal (base 8) | 76121 |
| Hexadecimal (base 16) | 7C51 |
| Base 3 | 1121122201 |
| As time | 31825 seconds = 8 h 50 min 25 s |
Is 31825 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (31825 ÷ 5 = 6365) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 1) | 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 5) | 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 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 31825 a prime number?
No. 31825 = × 19 × 67, so it is divisible by 5.
What are the factors of 31825?
1, 5, 19, 25, 67, 95, 335, 475, 1273, 1675, 6365, 31825.
What is 31825 in binary?
111110001010001 (hexadecimal 7C51, octal 76121).
What is the square root of 31825?
About 178.3956, exactly 5√1273.
Is 31825 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 31825?
31825 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 19.