The number 20480
20480 is a composite number with 26 divisors. Its prime factorisation is × 5. Divisors (26): 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 256, 320 … 20480.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20480 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20480 is composite. Its prime factorisation is
- 3
The divisors add up to 49146; without 20480 itself that is 28666, so 20480 is abundant (28666 is more than 20480). Euler's totient φ(20480) = 8192 numbers up to 20480 share no factor with it.
- 4
The digits of 20480 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 17 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20480 = 2^{12} \times 5 \]20480 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 26 |
| Sum of divisors | 49146 |
| Euler totient φ(n) | 8192 |
| Square | 419430400 |
| Cube | 8589934592000 |
| Square root | 143.108351 (= 64√5) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 17 |
| Scientific notation | 2.048 × |
20480 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand four hundred and eighty |
| Binary (base 2) | 101000000000000 |
| Octal (base 8) | 50000 |
| Hexadecimal (base 16) | 5000 |
| Base 3 | 1001002112 |
| As time | 20480 seconds = 5 h 41 min 20 s |
Is 20480 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (20480 ÷ 2 = 10240) | 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 (20480 ÷ 4 = 5120) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (20480 ÷ 5 = 4096) | 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 (20480 ÷ 8 = 2560) | 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 (20480 ÷ 10 = 2048) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | 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 20480 a prime number?
No. 20480 = × 5, so it is divisible by 2.
What are the factors of 20480?
1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 256, 320, 512, 640, 1024, 1280, 2048, 2560, 4096, 5120, 10240, 20480.
What is 20480 in binary?
101000000000000 (hexadecimal 5000, octal 50000).
What is the square root of 20480?
About 143.1084, exactly 64√5.
Is 20480 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 20480?
It is a composite number with 26 divisors.