The number 20955
20955 is a composite number with 16 divisors. Its prime factorisation is 3 × 5 × 11 × 127. Divisors (16): 1, 3, 5, 11, 15, 33, 55, 127, 165, 381, 635, 1397, 1905, 4191, 6985, 20955.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20955 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20955 is composite. Its prime factorisation is
- 3
The divisors add up to 36864; without 20955 itself that is 15909, so 20955 is deficient (15909 is less than 20955). Euler's totient φ(20955) = 10080 numbers up to 20955 share no factor with it.
- 4
The digits of 20955 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 87 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20955 = 3 \times 5 \times 11 \times 127 \]
20955 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 36864 |
| Euler totient φ(n) | 10080 |
| Square | 439112025 |
| Cube | 9201592483875 |
| Square root | 144.758419 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 87 |
| Scientific notation | 2.0955 × |
20955 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand nine hundred and fifty-five |
| Binary (base 2) | 101000111011011 |
| Octal (base 8) | 50733 |
| Hexadecimal (base 16) | 51DB |
| Base 3 | 1001202010 |
| As time | 20955 seconds = 5 h 49 min 15 s |
Is 20955 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (20955 ÷ 3 = 6985) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (20955 ÷ 5 = 4191) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | 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 | No (remainder 3) | 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 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (20955 ÷ 11 = 1905) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20955 a prime number?
No. 20955 = 3 × 5 × 11 × 127, so it is divisible by 3.
What are the factors of 20955?
1, 3, 5, 11, 15, 33, 55, 127, 165, 381, 635, 1397, 1905, 4191, 6985, 20955.
What is 20955 in binary?
101000111011011 (hexadecimal 51DB, octal 50733).
What is the square root of 20955?
About 144.7584.
Is 20955 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 20955?
It is a composite number with 16 divisors.