The number 6689
6689 is a twin prime (6689 and 6691 are both prime) and the 862nd prime number. Its only divisors are 1 and 6689.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 6689: a twin prime (6689 and 6691 are both prime); the 862nd prime number.
- 2
6689 is prime, so its only factors are 1 and 6689. It is the 862nd prime; the next prime is 6691 and the one before is 6679.
- 3
The divisors add up to 6690; without 6689 itself that is 1, so 6689 is deficient (1 is less than 6689). Euler's totient φ(6689) = 6688 numbers up to 6689 share no factor with it.
- 4
The digits of 6689 add up to 29, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 44 steps to reach 1.
6689 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 6690 |
| Euler totient φ(n) | 6688 |
| Square | 44742721 |
| Cube | 299284060769 |
| Square root | 81.786307 |
| Digit sum / digital root | 29 / 2 |
| Collatz steps to 1 | 44 |
| Scientific notation | 6.689 × |
6689 in other forms
| Form | Value |
|---|---|
| In words | six thousand six hundred and eighty-nine |
| Binary (base 2) | 1101000100001 |
| Octal (base 8) | 15041 |
| Hexadecimal (base 16) | 1A21 |
| Base 3 | 100011202 |
| As time | 6689 seconds = 1 h 51 min 29 s |
Is 6689 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | 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 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 1) | 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 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 6689 a prime number?
Yes. 6689 is divisible only by 1 and itself.
What are the factors of 6689?
1, 6689.
What is 6689 in binary?
1101000100001 (hexadecimal 1A21, octal 15041).
What is the square root of 6689?
About 81.7863.
Is 6689 divisible by 3?
No. Its digits add up to 29, which is not a multiple of 3.
What is special about the number 6689?
6689 is a twin prime (6689 and 6691 are both prime); the 862nd prime number.