The number 30828
30828 is a composite number with 24 divisors. Its prime factorisation is × 3 × 7 × 367. Divisors (24): 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84, 367, 734, 1101, 1468 … 30828.
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How to work it out
- 1
What is special about 30828: a Harshad number: divisible by its digit sum 21.
- 2
30828 is composite. Its prime factorisation is
- 3
The divisors add up to 82432; without 30828 itself that is 51604, so 30828 is abundant (51604 is more than 30828). Euler's totient φ(30828) = 8784 numbers up to 30828 share no factor with it.
- 4
The digits of 30828 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 72 steps to reach 1.
LaTeX source of the formulas on this page
\[ 30828 = 2^{2} \times 3 \times 7 \times 367 \]30828 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 82432 |
| Euler totient φ(n) | 8784 |
| Square | 950365584 |
| Cube | 29297870223552 |
| Square root | 175.579042 (= 2√7707) |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 72 |
| Scientific notation | 3.0828 × |
30828 in other forms
| Form | Value |
|---|---|
| In words | thirty thousand eight hundred and twenty-eight |
| Binary (base 2) | 111100001101100 |
| Octal (base 8) | 74154 |
| Hexadecimal (base 16) | 786C |
| Base 3 | 1120021210 |
| As time | 30828 seconds = 8 h 33 min 48 s |
Is 30828 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (30828 ÷ 2 = 15414) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (30828 ÷ 3 = 10276) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (30828 ÷ 4 = 7707) | 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 | Yes (30828 ÷ 6 = 5138) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (30828 ÷ 7 = 4404) | 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 3) | 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 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (30828 ÷ 12 = 2569) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 30828 a prime number?
No. 30828 = × 3 × 7 × 367, so it is divisible by 2.
What are the factors of 30828?
1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84, 367, 734, 1101, 1468, 2202, 2569, 4404, 5138, 7707, 10276, 15414, 30828.
What is 30828 in binary?
111100001101100 (hexadecimal 786C, octal 74154).
What is the square root of 30828?
About 175.5790, exactly 2√7707.
Is 30828 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 30828?
30828 is a Harshad number: divisible by its digit sum 21.