The number 308
308 is a composite number with 12 divisors. Its prime factorisation is × 7 × 11. Divisors (12): 1, 2, 4, 7, 11, 14, 22, 28, 44, 77, 154, 308.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 308: a Harshad number: divisible by its digit sum 11.
- 2
308 is composite. Its prime factorisation is
- 3
The divisors add up to 672; without 308 itself that is 364, so 308 is abundant (364 is more than 308). Euler's totient φ(308) = 120 numbers up to 308 share no factor with it.
- 4
The digits of 308 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 24 steps to reach 1.
LaTeX source of the formulas on this page
\[ 308 = 2^{2} \times 7 \times 11 \]308 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 672 |
| Euler totient φ(n) | 120 |
| Square | 94864 |
| Cube | 29218112 |
| Square root | 17.549929 (= 2√77) |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 24 |
| Scientific notation | 3.08 × |
308 in other forms
| Form | Value |
|---|---|
| In words | three hundred and eight |
| Roman numerals | CCCVIII |
| Binary (base 2) | 100110100 |
| Octal (base 8) | 464 |
| Hexadecimal (base 16) | 134 |
| Base 3 | 102102 |
| As time | 308 seconds = 5 min 8 s |
Is 308 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (308 ÷ 2 = 154) | 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 (308 ÷ 4 = 77) | 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 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (308 ÷ 7 = 44) | 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 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (308 ÷ 11 = 28) | 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 308 a prime number?
No. 308 = × 7 × 11, so it is divisible by 2.
What are the factors of 308?
1, 2, 4, 7, 11, 14, 22, 28, 44, 77, 154, 308.
What is 308 in binary?
100110100 (hexadecimal 134, octal 464).
What is the square root of 308?
About 17.5499, exactly 2√77.
What is 308 in Roman numerals?
CCCVIII.
Is 308 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 308?
308 is a Harshad number: divisible by its digit sum 11.