The number 20741
20741 is a composite number with 4 divisors. Its prime factorisation is 7 × 2963. Divisors (4): 1, 7, 2963, 20741.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20741: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 2963, the product of two primes.
- 2
20741 is composite. Its prime factorisation is
- 3
The divisors add up to 23712; without 20741 itself that is 2971, so 20741 is deficient (2971 is less than 20741). Euler's totient φ(20741) = 17772 numbers up to 20741 share no factor with it.
- 4
The digits of 20741 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 43 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20741 = 7 \times 2963 \]
20741 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 23712 |
| Euler totient φ(n) | 17772 |
| Square | 430189081 |
| Cube | 8922551729021 |
| Square root | 144.017360 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 43 |
| Scientific notation | 2.0741 × |
20741 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand seven hundred and forty-one |
| Binary (base 2) | 101000100000101 |
| Octal (base 8) | 50405 |
| Hexadecimal (base 16) | 5105 |
| Base 3 | 1001110012 |
| As time | 20741 seconds = 5 h 45 min 41 s |
Is 20741 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 2) | 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 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (20741 ÷ 7 = 2963) | 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 5) | 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 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20741 a prime number?
No. 20741 = 7 × 2963, so it is divisible by 7.
What are the factors of 20741?
1, 7, 2963, 20741.
What is 20741 in binary?
101000100000101 (hexadecimal 5105, octal 50405).
What is the square root of 20741?
About 144.0174.
Is 20741 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 20741?
20741 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 7 × 2963, the product of two primes.