The number 28900
28900 is a perfect square (170²). Its prime factorisation is × × . Divisors (27): 1, 2, 4, 5, 10, 17, 20, 25, 34, 50, 68, 85, 100, 170, 289, 340 … 28900.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 28900: a perfect square (170²).
- 2
28900 is composite. Its prime factorisation is
- 3
The divisors add up to 66619; without 28900 itself that is 37719, so 28900 is abundant (37719 is more than 28900). Euler's totient φ(28900) = 10880 numbers up to 28900 share no factor with it.
- 4
The digits of 28900 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 46 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28900 = 2^{2} \times 5^{2} \times 17^{2} \]28900 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 27 |
| Sum of divisors | 66619 |
| Euler totient φ(n) | 10880 |
| Square | 835210000 |
| Cube | 24137569000000 |
| Square root | 170 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 46 |
| Scientific notation | 2.89 × |
| Perfect power |
28900 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand nine hundred |
| Binary (base 2) | 111000011100100 |
| Octal (base 8) | 70344 |
| Hexadecimal (base 16) | 70E4 |
| Base 3 | 1110122101 |
| As time | 28900 seconds = 8 h 1 min 40 s |
Is 28900 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28900 ÷ 2 = 14450) | 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 (28900 ÷ 4 = 7225) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (28900 ÷ 5 = 5780) | 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 4) | 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 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (28900 ÷ 10 = 2890) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 3) | 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 28900 a prime number?
No. 28900 = × × , so it is divisible by 2.
What are the factors of 28900?
1, 2, 4, 5, 10, 17, 20, 25, 34, 50, 68, 85, 100, 170, 289, 340, 425, 578, 850, 1156, 1445, 1700, 2890, 5780, 7225, 14450, 28900.
What is 28900 in binary?
111000011100100 (hexadecimal 70E4, octal 70344).
What is the square root of 28900?
170, because 170 × 170 = 28900.
Is 28900 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 28900?
28900 is a perfect square (170²).