The number 28428
28428 is a composite number with 24 divisors. Its prime factorisation is × 3 × 23 × 103. Divisors (24): 1, 2, 3, 4, 6, 12, 23, 46, 69, 92, 103, 138, 206, 276, 309, 412 … 28428.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
28428 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
28428 is composite. Its prime factorisation is
- 3
The divisors add up to 69888; without 28428 itself that is 41460, so 28428 is abundant (41460 is more than 28428). Euler's totient φ(28428) = 8976 numbers up to 28428 share no factor with it.
- 4
The digits of 28428 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 59 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28428 = 2^{2} \times 3 \times 23 \times 103 \]28428 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 69888 |
| Euler totient φ(n) | 8976 |
| Square | 808151184 |
| Cube | 22974121858752 |
| Square root | 168.606050 (= 2√7107) |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 59 |
| Scientific notation | 2.8428 × |
28428 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand four hundred and twenty-eight |
| Binary (base 2) | 110111100001100 |
| Octal (base 8) | 67414 |
| Hexadecimal (base 16) | 6F0C |
| Base 3 | 1102222220 |
| As time | 28428 seconds = 7 h 53 min 48 s |
Is 28428 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28428 ÷ 2 = 14214) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (28428 ÷ 3 = 9476) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (28428 ÷ 4 = 7107) | 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 (28428 ÷ 6 = 4738) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 6) | 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 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (28428 ÷ 12 = 2369) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 28428 a prime number?
No. 28428 = × 3 × 23 × 103, so it is divisible by 2.
What are the factors of 28428?
1, 2, 3, 4, 6, 12, 23, 46, 69, 92, 103, 138, 206, 276, 309, 412, 618, 1236, 2369, 4738, 7107, 9476, 14214, 28428.
What is 28428 in binary?
110111100001100 (hexadecimal 6F0C, octal 67414).
What is the square root of 28428?
About 168.6060, exactly 2√7107.
Is 28428 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 28428?
It is a composite number with 24 divisors.