The number 20904
20904 is a composite number with 32 divisors. Its prime factorisation is × 3 × 13 × 67. Divisors (32): 1, 2, 3, 4, 6, 8, 12, 13, 24, 26, 39, 52, 67, 78, 104, 134 … 20904.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20904 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20904 is composite. Its prime factorisation is
- 3
The divisors add up to 57120; without 20904 itself that is 36216, so 20904 is abundant (36216 is more than 20904). Euler's totient φ(20904) = 6336 numbers up to 20904 share no factor with it.
- 4
The digits of 20904 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 30 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20904 = 2^{3} \times 3 \times 13 \times 67 \]20904 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 57120 |
| Euler totient φ(n) | 6336 |
| Square | 436977216 |
| Cube | 9134571723264 |
| Square root | 144.582157 (= 2√5226) |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 30 |
| Scientific notation | 2.0904 × |
20904 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand nine hundred and four |
| Binary (base 2) | 101000110101000 |
| Octal (base 8) | 50650 |
| Hexadecimal (base 16) | 51A8 |
| Base 3 | 1001200020 |
| As time | 20904 seconds = 5 h 48 min 24 s |
Is 20904 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (20904 ÷ 2 = 10452) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (20904 ÷ 3 = 6968) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (20904 ÷ 4 = 5226) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (20904 ÷ 6 = 3484) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 (20904 ÷ 8 = 2613) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | 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 | Yes (20904 ÷ 12 = 1742) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20904 a prime number?
No. 20904 = × 3 × 13 × 67, so it is divisible by 2.
What are the factors of 20904?
1, 2, 3, 4, 6, 8, 12, 13, 24, 26, 39, 52, 67, 78, 104, 134, 156, 201, 268, 312, 402, 536, 804, 871, 1608, 1742, 2613, 3484, 5226, 6968, 10452, 20904.
What is 20904 in binary?
101000110101000 (hexadecimal 51A8, octal 50650).
What is the square root of 20904?
About 144.5822, exactly 2√5226.
Is 20904 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 20904?
It is a composite number with 32 divisors.