The number 20131
20131 is a composite number with 4 divisors. Its prime factorisation is 41 × 491. Divisors (4): 1, 41, 491, 20131.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 20131: a semiprime: 41 × 491, the product of two primes.
- 2
20131 is composite. Its prime factorisation is
- 3
The divisors add up to 20664; without 20131 itself that is 533, so 20131 is deficient (533 is less than 20131). Euler's totient φ(20131) = 19600 numbers up to 20131 share no factor with it.
- 4
The digits of 20131 add up to 7, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 43 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20131 = 41 \times 491 \]
20131 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 20664 |
| Euler totient φ(n) | 19600 |
| Square | 405257161 |
| Cube | 8158231908091 |
| Square root | 141.883755 |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 43 |
| Scientific notation | 2.0131 × |
20131 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand one hundred and thirty-one |
| Binary (base 2) | 100111010100011 |
| Octal (base 8) | 47243 |
| Hexadecimal (base 16) | 4EA3 |
| Base 3 | 1000121121 |
| As time | 20131 seconds = 5 h 35 min 31 s |
Is 20131 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 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 7) | 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 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20131 a prime number?
No. 20131 = 41 × 491, so it is divisible by 41.
What are the factors of 20131?
1, 41, 491, 20131.
What is 20131 in binary?
100111010100011 (hexadecimal 4EA3, octal 47243).
What is the square root of 20131?
About 141.8838.
Is 20131 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 20131?
20131 is a semiprime: 41 × 491, the product of two primes.