The number 1223
1223 is the 200th prime number. Its only divisors are 1 and 1223.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1223: the 200th prime number.
- 2
1223 is prime, so its only factors are 1 and 1223. It is the 200th prime; the next prime is 1229 and the one before is 1217.
- 3
The divisors add up to 1224; without 1223 itself that is 1, so 1223 is deficient (1 is less than 1223). Euler's totient φ(1223) = 1222 numbers up to 1223 share no factor with it.
- 4
The digits of 1223 add up to 8, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 132 steps to reach 1.
1223 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 1224 |
| Euler totient φ(n) | 1222 |
| Square | 1495729 |
| Cube | 1829276567 |
| Square root | 34.971417 |
| Digit sum / digital root | 8 / 8 |
| Collatz steps to 1 | 132 |
| Scientific notation | 1.223 × |
1223 in other forms
| Form | Value |
|---|---|
| In words | one thousand two hundred and twenty-three |
| Roman numerals | MCCXXIII |
| Binary (base 2) | 10011000111 |
| Octal (base 8) | 2307 |
| Hexadecimal (base 16) | 4C7 |
| Base 3 | 1200022 |
| As time | 1223 seconds = 20 min 23 s |
Is 1223 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 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1223 a prime number?
Yes. 1223 is divisible only by 1 and itself.
What are the factors of 1223?
1, 1223.
What is 1223 in binary?
10011000111 (hexadecimal 4C7, octal 2307).
What is the square root of 1223?
About 34.9714.
What is 1223 in Roman numerals?
MCCXXIII.
Is 1223 divisible by 3?
No. Its digits add up to 8, which is not a multiple of 3.
What is special about the number 1223?
1223 is the 200th prime number.