The number 7123
7123 is a composite number with 4 divisors. Its prime factorisation is 17 × 419. Divisors (4): 1, 17, 419, 7123.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7123: a semiprime: 17 × 419, the product of two primes.
- 2
7123 is composite. Its prime factorisation is
- 3
The divisors add up to 7560; without 7123 itself that is 437, so 7123 is deficient (437 is less than 7123). Euler's totient φ(7123) = 6688 numbers up to 7123 share no factor with it.
- 4
The digits of 7123 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 49 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7123 = 17 \times 419 \]
7123 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 7560 |
| Euler totient φ(n) | 6688 |
| Square | 50737129 |
| Cube | 361400569867 |
| Square root | 84.397867 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 49 |
| Scientific notation | 7.123 × |
7123 in other forms
| Form | Value |
|---|---|
| In words | seven thousand one hundred and twenty-three |
| Binary (base 2) | 1101111010011 |
| Octal (base 8) | 15723 |
| Hexadecimal (base 16) | 1BD3 |
| Base 3 | 100202211 |
| As time | 7123 seconds = 1 h 58 min 43 s |
Is 7123 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 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | 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 6) | 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 7123 a prime number?
No. 7123 = 17 × 419, so it is divisible by 17.
What are the factors of 7123?
1, 17, 419, 7123.
What is 7123 in binary?
1101111010011 (hexadecimal 1BD3, octal 15723).
What is the square root of 7123?
About 84.3979.
Is 7123 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 7123?
7123 is a semiprime: 17 × 419, the product of two primes.