The number 51831
51831 is a composite number with 12 divisors. Its prime factorisation is × 13 × 443. Divisors (12): 1, 3, 9, 13, 39, 117, 443, 1329, 3987, 5759, 17277, 51831.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 51831: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
51831 is composite. Its prime factorisation is
- 3
The divisors add up to 80808; without 51831 itself that is 28977, so 51831 is deficient (28977 is less than 51831). Euler's totient φ(51831) = 31824 numbers up to 51831 share no factor with it.
- 4
The digits of 51831 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 52 steps to reach 1.
LaTeX source of the formulas on this page
\[ 51831 = 3^{2} \times 13 \times 443 \]51831 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 80808 |
| Euler totient φ(n) | 31824 |
| Square | 2686452561 |
| Cube | 139241522689191 |
| Square root | 227.664226 (= 3√5759) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 52 |
| Scientific notation | 5.1831 × |
51831 in other forms
| Form | Value |
|---|---|
| In words | fifty-one thousand eight hundred and thirty-one |
| Binary (base 2) | 1100101001110111 |
| Octal (base 8) | 145167 |
| Hexadecimal (base 16) | CA77 |
| Base 3 | 2122002200 |
| As time | 51831 seconds = 14 h 23 min 51 s |
Is 51831 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 (51831 ÷ 3 = 17277) | 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 3) | 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 | Yes (51831 ÷ 9 = 5759) | 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 10) | 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 51831 a prime number?
No. 51831 = × 13 × 443, so it is divisible by 3.
What are the factors of 51831?
1, 3, 9, 13, 39, 117, 443, 1329, 3987, 5759, 17277, 51831.
What is 51831 in binary?
1100101001110111 (hexadecimal CA77, octal 145167).
What is the square root of 51831?
About 227.6642, exactly 3√5759.
Is 51831 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 51831?
51831 is a happy number: repeatedly adding the squares of its digits reaches 1.