The number 13123
13123 is a composite number with 4 divisors. Its prime factorisation is 11 × 1193. Divisors (4): 1, 11, 1193, 13123.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 13123: a semiprime: 11 × 1193, the product of two primes.
- 2
13123 is composite. Its prime factorisation is
- 3
The divisors add up to 14328; without 13123 itself that is 1205, so 13123 is deficient (1205 is less than 13123). Euler's totient φ(13123) = 11920 numbers up to 13123 share no factor with it.
- 4
The digits of 13123 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13123 = 11 \times 1193 \]
13123 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 14328 |
| Euler totient φ(n) | 11920 |
| Square | 172213129 |
| Cube | 2259952891867 |
| Square root | 114.555663 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 76 |
| Scientific notation | 1.3123 × |
13123 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand one hundred and twenty-three |
| Binary (base 2) | 11001101000011 |
| Octal (base 8) | 31503 |
| Hexadecimal (base 16) | 3343 |
| Base 3 | 200000001 |
| As time | 13123 seconds = 3 h 38 min 43 s |
Is 13123 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 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 (13123 ÷ 11 = 1193) | 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 13123 a prime number?
No. 13123 = 11 × 1193, so it is divisible by 11.
What are the factors of 13123?
1, 11, 1193, 13123.
What is 13123 in binary?
11001101000011 (hexadecimal 3343, octal 31503).
What is the square root of 13123?
About 114.5557.
Is 13123 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 13123?
13123 is a semiprime: 11 × 1193, the product of two primes.