The number 8123
8123 is the 1022nd prime number. Its only divisors are 1 and 8123.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 8123: the 1022nd prime number.
- 2
8123 is prime, so its only factors are 1 and 8123. It is the 1022nd prime; the next prime is 8147 and the one before is 8117.
- 3
The divisors add up to 8124; without 8123 itself that is 1, so 8123 is deficient (1 is less than 8123). Euler's totient φ(8123) = 8122 numbers up to 8123 share no factor with it.
- 4
The digits of 8123 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 39 steps to reach 1.
8123 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 8124 |
| Euler totient φ(n) | 8122 |
| Square | 65983129 |
| Cube | 535980956867 |
| Square root | 90.127687 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 39 |
| Scientific notation | 8.123 × |
8123 in other forms
| Form | Value |
|---|---|
| In words | eight thousand one hundred and twenty-three |
| Binary (base 2) | 1111110111011 |
| Octal (base 8) | 17673 |
| Hexadecimal (base 16) | 1FBB |
| Base 3 | 102010212 |
| As time | 8123 seconds = 2 h 15 min 23 s |
Is 8123 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 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | 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 3) | 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 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 8123 a prime number?
Yes. 8123 is divisible only by 1 and itself.
What are the factors of 8123?
1, 8123.
What is 8123 in binary?
1111110111011 (hexadecimal 1FBB, octal 17673).
What is the square root of 8123?
About 90.1277.
Is 8123 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 8123?
8123 is the 1022nd prime number.