The number 28020
28020 is a composite number with 24 divisors. Its prime factorisation is × 3 × 5 × 467. Divisors (24): 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 467, 934, 1401, 1868 … 28020.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 28020: a Harshad number: divisible by its digit sum 12.
- 2
28020 is composite. Its prime factorisation is
- 3
The divisors add up to 78624; without 28020 itself that is 50604, so 28020 is abundant (50604 is more than 28020). Euler's totient φ(28020) = 7456 numbers up to 28020 share no factor with it.
- 4
The digits of 28020 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 33 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28020 = 2^{2} \times 3 \times 5 \times 467 \]28020 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 78624 |
| Euler totient φ(n) | 7456 |
| Square | 785120400 |
| Cube | 21999073608000 |
| Square root | 167.391756 (= 2√7005) |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 33 |
| Scientific notation | 2.802 × |
28020 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand and twenty |
| Binary (base 2) | 110110101110100 |
| Octal (base 8) | 66564 |
| Hexadecimal (base 16) | 6D74 |
| Base 3 | 1102102210 |
| As time | 28020 seconds = 7 h 47 min 0 s |
Is 28020 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (28020 ÷ 2 = 14010) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (28020 ÷ 3 = 9340) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (28020 ÷ 4 = 7005) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (28020 ÷ 5 = 5604) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (28020 ÷ 6 = 4670) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (28020 ÷ 10 = 2802) | 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 | Yes (28020 ÷ 12 = 2335) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 28020 a prime number?
No. 28020 = × 3 × 5 × 467, so it is divisible by 2.
What are the factors of 28020?
1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 467, 934, 1401, 1868, 2335, 2802, 4670, 5604, 7005, 9340, 14010, 28020.
What is 28020 in binary?
110110101110100 (hexadecimal 6D74, octal 66564).
What is the square root of 28020?
About 167.3918, exactly 2√7005.
Is 28020 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 28020?
28020 is a Harshad number: divisible by its digit sum 12.