The number 8125
8125 is a composite number with 10 divisors. Its prime factorisation is Ć 13. Divisors (10): 1, 5, 13, 25, 65, 125, 325, 625, 1625, 8125.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 8125: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
8125 is composite. Its prime factorisation is
- 3
The divisors add up to 10934; without 8125 itself that is 2809, so 8125 is deficient (2809 is less than 8125). Euler's totient Ļ(8125) = 6000 numbers up to 8125 share no factor with it.
- 4
The digits of 8125 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 65 steps to reach 1.
LaTeX source of the formulas on this page
\[ 8125 = 5^{4} \times 13 \]8125 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 10 |
| Sum of divisors | 10934 |
| Euler totient Ļ(n) | 6000 |
| Square | 66015625 |
| Cube | 536376953125 |
| Square root | 90.138782 (= 25ā13) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 65 |
| Scientific notation | 8.125 Ć |
8125 in other forms
| Form | Value |
|---|---|
| In words | eight thousand one hundred and twenty-five |
| Binary (base 2) | 1111110111101 |
| Octal (base 8) | 17675 |
| Hexadecimal (base 16) | 1FBD |
| Base 3 | 102010221 |
| As time | 8125 seconds = 2 h 15 min 25 s |
Is 8125 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 (8125 Ć· 5 = 1625) | 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 5) | 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 5) | 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 | No (remainder 5) | 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 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 8125 a prime number?
No. 8125 = Ć 13, so it is divisible by 5.
What are the factors of 8125?
1, 5, 13, 25, 65, 125, 325, 625, 1625, 8125.
What is 8125 in binary?
1111110111101 (hexadecimal 1FBD, octal 17675).
What is the square root of 8125?
About 90.1388, exactly 25ā13.
Is 8125 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 8125?
8125 is a happy number: repeatedly adding the squares of its digits reaches 1.