The number 1123
1123 is the 188th prime number. Its only divisors are 1 and 1123.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1123: the 188th prime number.
- 2
1123 is prime, so its only factors are 1 and 1123. It is the 188th prime; the next prime is 1129 and the one before is 1117.
- 3
The divisors add up to 1124; without 1123 itself that is 1, so 1123 is deficient (1 is less than 1123). Euler's totient φ(1123) = 1122 numbers up to 1123 share no factor with it.
- 4
The digits of 1123 add up to 7, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 44 steps to reach 1.
1123 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 1124 |
| Euler totient φ(n) | 1122 |
| Square | 1261129 |
| Cube | 1416247867 |
| Square root | 33.511192 |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 44 |
| Scientific notation | 1.123 × |
1123 in other forms
| Form | Value |
|---|---|
| In words | one thousand one hundred and twenty-three |
| Roman numerals | MCXXIII |
| Binary (base 2) | 10001100011 |
| Octal (base 8) | 2143 |
| Hexadecimal (base 16) | 463 |
| Base 3 | 1112121 |
| As time | 1123 seconds = 18 min 43 s |
Is 1123 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 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 1) | 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 7) | 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 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1123 a prime number?
Yes. 1123 is divisible only by 1 and itself.
What are the factors of 1123?
1, 1123.
What is 1123 in binary?
10001100011 (hexadecimal 463, octal 2143).
What is the square root of 1123?
About 33.5112.
What is 1123 in Roman numerals?
MCXXIII.
Is 1123 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 1123?
1123 is the 188th prime number.