The number 7124
7124 is a composite number with 12 divisors. Its prime factorisation is × 13 × 137. Divisors (12): 1, 2, 4, 13, 26, 52, 137, 274, 548, 1781, 3562, 7124.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7124: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
7124 is composite. Its prime factorisation is
- 3
The divisors add up to 13524; without 7124 itself that is 6400, so 7124 is deficient (6400 is less than 7124). Euler's totient φ(7124) = 3264 numbers up to 7124 share no factor with it.
- 4
The digits of 7124 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 75 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7124 = 2^{2} \times 13 \times 137 \]7124 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 13524 |
| Euler totient φ(n) | 3264 |
| Square | 50751376 |
| Cube | 361552802624 |
| Square root | 84.403791 (= 2√1781) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 75 |
| Scientific notation | 7.124 × |
7124 in other forms
| Form | Value |
|---|---|
| In words | seven thousand one hundred and twenty-four |
| Binary (base 2) | 1101111010100 |
| Octal (base 8) | 15724 |
| Hexadecimal (base 16) | 1BD4 |
| Base 3 | 100202212 |
| As time | 7124 seconds = 1 h 58 min 44 s |
Is 7124 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (7124 ÷ 2 = 3562) | 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 | Yes (7124 ÷ 4 = 1781) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 2) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 7124 a prime number?
No. 7124 = × 13 × 137, so it is divisible by 2.
What are the factors of 7124?
1, 2, 4, 13, 26, 52, 137, 274, 548, 1781, 3562, 7124.
What is 7124 in binary?
1101111010100 (hexadecimal 1BD4, octal 15724).
What is the square root of 7124?
About 84.4038, exactly 2√1781.
Is 7124 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 7124?
7124 is a happy number: repeatedly adding the squares of its digits reaches 1.