The number 28210
28210 is a composite number with 32 divisors. Its prime factorisation is 2 × 5 × 7 × 13 × 31. Divisors (32): 1, 2, 5, 7, 10, 13, 14, 26, 31, 35, 62, 65, 70, 91, 130, 155 … 28210.
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How to work it out
- 1
What is special about 28210: a Harshad number: divisible by its digit sum 13.
- 2
28210 is composite. Its prime factorisation is
- 3
The divisors add up to 64512; without 28210 itself that is 36302, so 28210 is abundant (36302 is more than 28210). Euler's totient φ(28210) = 8640 numbers up to 28210 share no factor with it.
- 4
The digits of 28210 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 59 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28210 = 2 \times 5 \times 7 \times 13 \times 31 \]
28210 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 64512 |
| Euler totient φ(n) | 8640 |
| Square | 795804100 |
| Cube | 22449633661000 |
| Square root | 167.958328 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 59 |
| Scientific notation | 2.821 × |
28210 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand two hundred and ten |
| Binary (base 2) | 110111000110010 |
| Octal (base 8) | 67062 |
| Hexadecimal (base 16) | 6E32 |
| Base 3 | 1102200211 |
| As time | 28210 seconds = 7 h 50 min 10 s |
Is 28210 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28210 ÷ 2 = 14105) | 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 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (28210 ÷ 5 = 5642) | 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 | Yes (28210 ÷ 7 = 4030) | 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 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (28210 ÷ 10 = 2821) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 28210 a prime number?
No. 28210 = 2 × 5 × 7 × 13 × 31, so it is divisible by 2.
What are the factors of 28210?
1, 2, 5, 7, 10, 13, 14, 26, 31, 35, 62, 65, 70, 91, 130, 155, 182, 217, 310, 403, 434, 455, 806, 910, 1085, 2015, 2170, 2821, 4030, 5642, 14105, 28210.
What is 28210 in binary?
110111000110010 (hexadecimal 6E32, octal 67062).
What is the square root of 28210?
About 167.9583.
Is 28210 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 28210?
28210 is a Harshad number: divisible by its digit sum 13.