The number 8428
8428 is a composite number with 18 divisors. Its prime factorisation is × × 43. Divisors (18): 1, 2, 4, 7, 14, 28, 43, 49, 86, 98, 172, 196, 301, 602, 1204, 2107 … 8428.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
8428 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
8428 is composite. Its prime factorisation is
- 3
The divisors add up to 17556; without 8428 itself that is 9128, so 8428 is abundant (9128 is more than 8428). Euler's totient φ(8428) = 3528 numbers up to 8428 share no factor with it.
- 4
The digits of 8428 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 158 steps to reach 1.
LaTeX source of the formulas on this page
\[ 8428 = 2^{2} \times 7^{2} \times 43 \]8428 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 17556 |
| Euler totient φ(n) | 3528 |
| Square | 71031184 |
| Cube | 598650818752 |
| Square root | 91.804139 (= 14√43) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 158 |
| Scientific notation | 8.428 × |
8428 in other forms
| Form | Value |
|---|---|
| In words | eight thousand four hundred and twenty-eight |
| Binary (base 2) | 10000011101100 |
| Octal (base 8) | 20354 |
| Hexadecimal (base 16) | 20EC |
| Base 3 | 102120011 |
| As time | 8428 seconds = 2 h 20 min 28 s |
Is 8428 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (8428 ÷ 2 = 4214) | 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 | Yes (8428 ÷ 4 = 2107) | 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 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (8428 ÷ 7 = 1204) | 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 4) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 8428 a prime number?
No. 8428 = × × 43, so it is divisible by 2.
What are the factors of 8428?
1, 2, 4, 7, 14, 28, 43, 49, 86, 98, 172, 196, 301, 602, 1204, 2107, 4214, 8428.
What is 8428 in binary?
10000011101100 (hexadecimal 20EC, octal 20354).
What is the square root of 8428?
About 91.8041, exactly 14√43.
Is 8428 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 8428?
It is a composite number with 18 divisors.