The number 2123
2123 is a composite number with 4 divisors. Its prime factorisation is 11 × 193. Divisors (4): 1, 11, 193, 2123.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 2123: a semiprime: 11 × 193, the product of two primes.
- 2
2123 is composite. Its prime factorisation is
- 3
The divisors add up to 2328; without 2123 itself that is 205, so 2123 is deficient (205 is less than 2123). Euler's totient φ(2123) = 1920 numbers up to 2123 share no factor with it.
- 4
The digits of 2123 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 32 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2123 = 11 \times 193 \]
2123 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 2328 |
| Euler totient φ(n) | 1920 |
| Square | 4507129 |
| Cube | 9568634867 |
| Square root | 46.076024 |
| Digit sum / digital root | 8 / 8 |
| Collatz steps to 1 | 32 |
| Scientific notation | 2.123 × |
2123 in other forms
| Form | Value |
|---|---|
| In words | two thousand one hundred and twenty-three |
| Roman numerals | MMCXXIII |
| Binary (base 2) | 100001001011 |
| Octal (base 8) | 4113 |
| Hexadecimal (base 16) | 84B |
| Base 3 | 2220122 |
| As time | 2123 seconds = 35 min 23 s |
Is 2123 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 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 3) | 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 | Yes (2123 ÷ 11 = 193) | 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 2123 a prime number?
No. 2123 = 11 × 193, so it is divisible by 11.
What are the factors of 2123?
1, 11, 193, 2123.
What is 2123 in binary?
100001001011 (hexadecimal 84B, octal 4113).
What is the square root of 2123?
About 46.0760.
What is 2123 in Roman numerals?
MMCXXIII.
Is 2123 divisible by 3?
No. Its digits add up to 8, which is not a multiple of 3.
What is special about the number 2123?
2123 is a semiprime: 11 × 193, the product of two primes.