The number 8390
8390 is a composite number with 8 divisors. Its prime factorisation is 2 × 5 × 839. Divisors (8): 1, 2, 5, 10, 839, 1678, 4195, 8390.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
8390 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
8390 is composite. Its prime factorisation is
- 3
The divisors add up to 15120; without 8390 itself that is 6730, so 8390 is deficient (6730 is less than 8390). Euler's totient φ(8390) = 3352 numbers up to 8390 share no factor with it.
- 4
The digits of 8390 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 65 steps to reach 1.
LaTeX source of the formulas on this page
\[ 8390 = 2 \times 5 \times 839 \]
8390 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 15120 |
| Euler totient φ(n) | 3352 |
| Square | 70392100 |
| Cube | 590589719000 |
| Square root | 91.596943 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 65 |
| Scientific notation | 8.39 × |
8390 in other forms
| Form | Value |
|---|---|
| In words | eight thousand three hundred and ninety |
| Binary (base 2) | 10000011000110 |
| Octal (base 8) | 20306 |
| Hexadecimal (base 16) | 20C6 |
| Base 3 | 102111202 |
| As time | 8390 seconds = 2 h 19 min 50 s |
Is 8390 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (8390 ÷ 2 = 4195) | 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 (8390 ÷ 5 = 1678) | 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 4) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (8390 ÷ 10 = 839) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 8390 a prime number?
No. 8390 = 2 × 5 × 839, so it is divisible by 2.
What are the factors of 8390?
1, 2, 5, 10, 839, 1678, 4195, 8390.
What is 8390 in binary?
10000011000110 (hexadecimal 20C6, octal 20306).
What is the square root of 8390?
About 91.5969.
Is 8390 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 8390?
It is a composite number with 8 divisors.