The number 2728
2728 is a composite number with 16 divisors. Its prime factorisation is × 11 × 31. Divisors (16): 1, 2, 4, 8, 11, 22, 31, 44, 62, 88, 124, 248, 341, 682, 1364, 2728.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
2728 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
2728 is composite. Its prime factorisation is
- 3
The divisors add up to 5760; without 2728 itself that is 3032, so 2728 is abundant (3032 is more than 2728). Euler's totient φ(2728) = 1200 numbers up to 2728 share no factor with it.
- 4
The digits of 2728 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 14 steps to reach 1.
LaTeX source of the formulas on this page
\[ 2728 = 2^{3} \times 11 \times 31 \]2728 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 5760 |
| Euler totient φ(n) | 1200 |
| Square | 7441984 |
| Cube | 20301732352 |
| Square root | 52.230259 (= 2√682) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 14 |
| Scientific notation | 2.728 × |
2728 in other forms
| Form | Value |
|---|---|
| In words | two thousand seven hundred and twenty-eight |
| Roman numerals | MMDCCXXVIII |
| Binary (base 2) | 101010101000 |
| Octal (base 8) | 5250 |
| Hexadecimal (base 16) | AA8 |
| Base 3 | 10202001 |
| As time | 2728 seconds = 45 min 28 s |
Is 2728 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (2728 ÷ 2 = 1364) | 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 (2728 ÷ 4 = 682) | 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 | No (remainder 5) | 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 | Yes (2728 ÷ 8 = 341) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 (2728 ÷ 11 = 248) | 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 2728 a prime number?
No. 2728 = × 11 × 31, so it is divisible by 2.
What are the factors of 2728?
1, 2, 4, 8, 11, 22, 31, 44, 62, 88, 124, 248, 341, 682, 1364, 2728.
What is 2728 in binary?
101010101000 (hexadecimal AA8, octal 5250).
What is the square root of 2728?
About 52.2303, exactly 2√682.
What is 2728 in Roman numerals?
MMDCCXXVIII.
Is 2728 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 2728?
It is a composite number with 16 divisors.