The number 20920
20920 is a composite number with 16 divisors. Its prime factorisation is × 5 × 523. Divisors (16): 1, 2, 4, 5, 8, 10, 20, 40, 523, 1046, 2092, 2615, 4184, 5230, 10460, 20920.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20920 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20920 is composite. Its prime factorisation is
- 3
The divisors add up to 47160; without 20920 itself that is 26240, so 20920 is abundant (26240 is more than 20920). Euler's totient φ(20920) = 8352 numbers up to 20920 share no factor with it.
- 4
The digits of 20920 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 180 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20920 = 2^{3} \times 5 \times 523 \]20920 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 47160 |
| Euler totient φ(n) | 8352 |
| Square | 437646400 |
| Cube | 9155562688000 |
| Square root | 144.637478 (= 2√5230) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 180 |
| Scientific notation | 2.092 × |
20920 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand nine hundred and twenty |
| Binary (base 2) | 101000110111000 |
| Octal (base 8) | 50670 |
| Hexadecimal (base 16) | 51B8 |
| Base 3 | 1001200211 |
| As time | 20920 seconds = 5 h 48 min 40 s |
Is 20920 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (20920 ÷ 2 = 10460) | 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 (20920 ÷ 4 = 5230) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (20920 ÷ 5 = 4184) | 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 | Yes (20920 ÷ 8 = 2615) | 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 (20920 ÷ 10 = 2092) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20920 a prime number?
No. 20920 = × 5 × 523, so it is divisible by 2.
What are the factors of 20920?
1, 2, 4, 5, 8, 10, 20, 40, 523, 1046, 2092, 2615, 4184, 5230, 10460, 20920.
What is 20920 in binary?
101000110111000 (hexadecimal 51B8, octal 50670).
What is the square root of 20920?
About 144.6375, exactly 2√5230.
Is 20920 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 20920?
It is a composite number with 16 divisors.