The number 679
679 is a composite number with 4 divisors. Its prime factorisation is 7 × 97. Divisors (4): 1, 7, 97, 679.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 679: a semiprime: 7 × 97, the product of two primes.
- 2
679 is composite. Its prime factorisation is
- 3
The divisors add up to 784; without 679 itself that is 105, so 679 is deficient (105 is less than 679). Euler's totient φ(679) = 576 numbers up to 679 share no factor with it.
- 4
The digits of 679 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 64 steps to reach 1.
LaTeX source of the formulas on this page
\[ 679 = 7 \times 97 \]
679 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 784 |
| Euler totient φ(n) | 576 |
| Square | 461041 |
| Cube | 313046839 |
| Square root | 26.057628 |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 64 |
| Scientific notation | 6.79 × |
679 in other forms
| Form | Value |
|---|---|
| In words | six hundred and seventy-nine |
| Roman numerals | DCLXXIX |
| Binary (base 2) | 1010100111 |
| Octal (base 8) | 1247 |
| Hexadecimal (base 16) | 2A7 |
| Base 3 | 221011 |
| As time | 679 seconds = 11 min 19 s |
Is 679 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 4) | 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 | Yes (679 ÷ 7 = 97) | 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 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 679 a prime number?
No. 679 = 7 × 97, so it is divisible by 7.
What are the factors of 679?
1, 7, 97, 679.
What is 679 in binary?
1010100111 (hexadecimal 2A7, octal 1247).
What is the square root of 679?
About 26.0576.
What is 679 in Roman numerals?
DCLXXIX.
Is 679 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 679?
679 is a semiprime: 7 × 97, the product of two primes.