The number 1789
1789 is a twin prime (1787 and 1789 are both prime) and the 278th prime number. Its only divisors are 1 and 1789.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1789: a twin prime (1787 and 1789 are both prime); the 278th prime number.
- 2
1789 is prime, so its only factors are 1 and 1789. It is the 278th prime; the next prime is 1801 and the one before is 1787.
- 3
The divisors add up to 1790; without 1789 itself that is 1, so 1789 is deficient (1 is less than 1789). Euler's totient φ(1789) = 1788 numbers up to 1789 share no factor with it.
- 4
The digits of 1789 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 99 steps to reach 1.
1789 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 1790 |
| Euler totient φ(n) | 1788 |
| Square | 3200521 |
| Cube | 5725732069 |
| Square root | 42.296572 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 99 |
| Scientific notation | 1.789 × |
1789 in other forms
| Form | Value |
|---|---|
| In words | one thousand seven hundred and eighty-nine |
| Roman numerals | MDCCLXXXIX |
| Binary (base 2) | 11011111101 |
| Octal (base 8) | 3375 |
| Hexadecimal (base 16) | 6FD |
| Base 3 | 2110021 |
| As time | 1789 seconds = 29 min 49 s |
Is 1789 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 | No (remainder 4) | 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 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 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 9) | 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 1789 a prime number?
Yes. 1789 is divisible only by 1 and itself.
What are the factors of 1789?
1, 1789.
What is 1789 in binary?
11011111101 (hexadecimal 6FD, octal 3375).
What is the square root of 1789?
About 42.2966.
What is 1789 in Roman numerals?
MDCCLXXXIX.
Is 1789 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 1789?
1789 is a twin prime (1787 and 1789 are both prime); the 278th prime number.