The number 28040
28040 is a composite number with 16 divisors. Its prime factorisation is × 5 × 701. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 701, 1402, 2804, 3505, 5608, 7010, 14020, 28040.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
28040 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
28040 is composite. Its prime factorisation is
- 3
The divisors add up to 63180; without 28040 itself that is 35140, so 28040 is abundant (35140 is more than 28040). Euler's totient φ(28040) = 11200 numbers up to 28040 share no factor with it.
- 4
The digits of 28040 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 59 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28040 = 2^{3} \times 5 \times 701 \]28040 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 63180 |
| Euler totient φ(n) | 11200 |
| Square | 786241600 |
| Cube | 22046214464000 |
| Square root | 167.451486 (= 2√7010) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 59 |
| Scientific notation | 2.804 × |
28040 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand and forty |
| Binary (base 2) | 110110110001000 |
| Octal (base 8) | 66610 |
| Hexadecimal (base 16) | 6D88 |
| Base 3 | 1102110112 |
| As time | 28040 seconds = 7 h 47 min 20 s |
Is 28040 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28040 ÷ 2 = 14020) | 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 (28040 ÷ 4 = 7010) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (28040 ÷ 5 = 5608) | 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 | 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 (28040 ÷ 8 = 3505) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (28040 ÷ 10 = 2804) | 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 28040 a prime number?
No. 28040 = × 5 × 701, so it is divisible by 2.
What are the factors of 28040?
1, 2, 4, 5, 8, 10, 20, 40, 701, 1402, 2804, 3505, 5608, 7010, 14020, 28040.
What is 28040 in binary?
110110110001000 (hexadecimal 6D88, octal 66610).
What is the square root of 28040?
About 167.4515, exactly 2√7010.
Is 28040 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 28040?
It is a composite number with 16 divisors.