The number 20471
20471 is a composite number with 4 divisors. Its prime factorisation is 11 × 1861. Divisors (4): 1, 11, 1861, 20471.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20471: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 11 × 1861, the product of two primes.
- 2
20471 is composite. Its prime factorisation is
- 3
The divisors add up to 22344; without 20471 itself that is 1873, so 20471 is deficient (1873 is less than 20471). Euler's totient φ(20471) = 18600 numbers up to 20471 share no factor with it.
- 4
The digits of 20471 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 118 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20471 = 11 \times 1861 \]
20471 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 22344 |
| Euler totient φ(n) | 18600 |
| Square | 419061841 |
| Cube | 8578614947111 |
| Square root | 143.076902 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 118 |
| Scientific notation | 2.0471 × |
20471 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand four hundred and seventy-one |
| Binary (base 2) | 100111111110111 |
| Octal (base 8) | 47767 |
| Hexadecimal (base 16) | 4FF7 |
| Base 3 | 1001002012 |
| As time | 20471 seconds = 5 h 41 min 11 s |
Is 20471 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 3) | 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 | No (remainder 3) | 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 7) | 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 | Yes (20471 ÷ 11 = 1861) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20471 a prime number?
No. 20471 = 11 × 1861, so it is divisible by 11.
What are the factors of 20471?
1, 11, 1861, 20471.
What is 20471 in binary?
100111111110111 (hexadecimal 4FF7, octal 47767).
What is the square root of 20471?
About 143.0769.
Is 20471 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 20471?
20471 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 11 × 1861, the product of two primes.