The number 2828
2828 is a composite number with 12 divisors. Its prime factorisation is × 7 × 101. Divisors (12): 1, 2, 4, 7, 14, 28, 101, 202, 404, 707, 1414, 2828.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
2828 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
2828 is composite. Its prime factorisation is
- 3
The divisors add up to 5712; without 2828 itself that is 2884, so 2828 is abundant (2884 is more than 2828). Euler's totient φ(2828) = 1200 numbers up to 2828 share no factor with it.
- 4
The digits of 2828 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 128 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2828 = 2^{2} \times 7 \times 101 \]2828 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 5712 |
| Euler totient φ(n) | 1200 |
| Square | 7997584 |
| Cube | 22617167552 |
| Square root | 53.178943 (= 2√707) |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 128 |
| Scientific notation | 2.828 × |
2828 in other forms
| Form | Value |
|---|---|
| In words | two thousand eight hundred and twenty-eight |
| Roman numerals | MMDCCCXXVIII |
| Binary (base 2) | 101100001100 |
| Octal (base 8) | 5414 |
| Hexadecimal (base 16) | B0C |
| Base 3 | 10212202 |
| As time | 2828 seconds = 47 min 8 s |
Is 2828 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (2828 ÷ 2 = 1414) | 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 (2828 ÷ 4 = 707) | 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 (2828 ÷ 7 = 404) | 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 | No (remainder 1) | 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 2828 a prime number?
No. 2828 = × 7 × 101, so it is divisible by 2.
What are the factors of 2828?
1, 2, 4, 7, 14, 28, 101, 202, 404, 707, 1414, 2828.
What is 2828 in binary?
101100001100 (hexadecimal B0C, octal 5414).
What is the square root of 2828?
About 53.1789, exactly 2√707.
What is 2828 in Roman numerals?
MMDCCCXXVIII.
Is 2828 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 2828?
It is a composite number with 12 divisors.