The number 1689
1689 is a composite number with 4 divisors. Its prime factorisation is 3 × 563. Divisors (4): 1, 3, 563, 1689.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1689: a semiprime: 3 × 563, the product of two primes.
- 2
1689 is composite. Its prime factorisation is
- 3
The divisors add up to 2256; without 1689 itself that is 567, so 1689 is deficient (567 is less than 1689). Euler's totient φ(1689) = 1124 numbers up to 1689 share no factor with it.
- 4
The digits of 1689 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 34 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1689 = 3 \times 563 \]
1689 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 2256 |
| Euler totient φ(n) | 1124 |
| Square | 2852721 |
| Cube | 4818245769 |
| Square root | 41.097445 |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 34 |
| Scientific notation | 1.689 × |
1689 in other forms
| Form | Value |
|---|---|
| In words | one thousand six hundred and eighty-nine |
| Roman numerals | MDCLXXXIX |
| Binary (base 2) | 11010011001 |
| Octal (base 8) | 3231 |
| Hexadecimal (base 16) | 699 |
| Base 3 | 2022120 |
| As time | 1689 seconds = 28 min 9 s |
Is 1689 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 | Yes (1689 ÷ 3 = 563) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 6) | 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 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1689 a prime number?
No. 1689 = 3 × 563, so it is divisible by 3.
What are the factors of 1689?
1, 3, 563, 1689.
What is 1689 in binary?
11010011001 (hexadecimal 699, octal 3231).
What is the square root of 1689?
About 41.0974.
What is 1689 in Roman numerals?
MDCLXXXIX.
Is 1689 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 1689?
1689 is a semiprime: 3 × 563, the product of two primes.