The number 28890
28890 is a composite number with 32 divisors. Its prime factorisation is 2 × × 5 × 107. Divisors (32): 1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 54, 90, 107, 135 … 28890.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 28890: a Harshad number: divisible by its digit sum 27.
- 2
28890 is composite. Its prime factorisation is
- 3
The divisors add up to 77760; without 28890 itself that is 48870, so 28890 is abundant (48870 is more than 28890). Euler's totient φ(28890) = 7632 numbers up to 28890 share no factor with it.
- 4
The digits of 28890 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 72 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28890 = 2 \times 3^{3} \times 5 \times 107 \]28890 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 77760 |
| Euler totient φ(n) | 7632 |
| Square | 834632100 |
| Cube | 24112521369000 |
| Square root | 169.970586 (= 3√3210) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 72 |
| Scientific notation | 2.889 × |
28890 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand eight hundred and ninety |
| Binary (base 2) | 111000011011010 |
| Octal (base 8) | 70332 |
| Hexadecimal (base 16) | 70DA |
| Base 3 | 1110122000 |
| As time | 28890 seconds = 8 h 1 min 30 s |
Is 28890 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28890 ÷ 2 = 14445) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (28890 ÷ 3 = 9630) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (28890 ÷ 5 = 5778) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (28890 ÷ 6 = 4815) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (28890 ÷ 9 = 3210) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (28890 ÷ 10 = 2889) | 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 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 28890 a prime number?
No. 28890 = 2 × × 5 × 107, so it is divisible by 2.
What are the factors of 28890?
1, 2, 3, 5, 6, 9, 10, 15, 18, 27, 30, 45, 54, 90, 107, 135, 214, 270, 321, 535, 642, 963, 1070, 1605, 1926, 2889, 3210, 4815, 5778, 9630, 14445, 28890.
What is 28890 in binary?
111000011011010 (hexadecimal 70DA, octal 70332).
What is the square root of 28890?
About 169.9706, exactly 3√3210.
Is 28890 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 28890?
28890 is a Harshad number: divisible by its digit sum 27.