The number 20977
20977 is a composite number with 4 divisors. Its prime factorisation is 11 × 1907. Divisors (4): 1, 11, 1907, 20977.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20977: a semiprime: 11 × 1907, the product of two primes.
- 2
20977 is composite. Its prime factorisation is
- 3
The divisors add up to 22896; without 20977 itself that is 1919, so 20977 is deficient (1919 is less than 20977). Euler's totient φ(20977) = 19060 numbers up to 20977 share no factor with it.
- 4
The digits of 20977 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 149 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20977 = 11 \times 1907 \]
20977 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 22896 |
| Euler totient φ(n) | 19060 |
| Square | 440034529 |
| Cube | 9230604314833 |
| Square root | 144.834388 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 149 |
| Scientific notation | 2.0977 × |
20977 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand nine hundred and seventy-seven |
| Binary (base 2) | 101000111110001 |
| Octal (base 8) | 50761 |
| Hexadecimal (base 16) | 51F1 |
| Base 3 | 1001202221 |
| As time | 20977 seconds = 5 h 49 min 37 s |
Is 20977 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 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | 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 | No (remainder 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (20977 ÷ 11 = 1907) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20977 a prime number?
No. 20977 = 11 × 1907, so it is divisible by 11.
What are the factors of 20977?
1, 11, 1907, 20977.
What is 20977 in binary?
101000111110001 (hexadecimal 51F1, octal 50761).
What is the square root of 20977?
About 144.8344.
Is 20977 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 20977?
20977 is a semiprime: 11 × 1907, the product of two primes.