The number 1813
1813 is a composite number with 6 divisors. Its prime factorisation is Ć 37. Divisors (6): 1, 7, 37, 49, 259, 1813.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
1813 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
1813 is composite. Its prime factorisation is
- 3
The divisors add up to 2166; without 1813 itself that is 353, so 1813 is deficient (353 is less than 1813). Euler's totient Ļ(1813) = 1512 numbers up to 1813 share no factor with it.
- 4
The digits of 1813 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 16 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1813 = 7^{2} \times 37 \]1813 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 2166 |
| Euler totient Ļ(n) | 1512 |
| Square | 3286969 |
| Cube | 5959274797 |
| Square root | 42.579338 (= 7ā37) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 16 |
| Scientific notation | 1.813 Ć |
1813 in other forms
| Form | Value |
|---|---|
| In words | one thousand eight hundred and thirteen |
| Roman numerals | MDCCCXIII |
| Binary (base 2) | 11100010101 |
| Octal (base 8) | 3425 |
| Hexadecimal (base 16) | 715 |
| Base 3 | 2111011 |
| As time | 1813 seconds = 30 min 13 s |
Is 1813 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 3) | 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 | Yes (1813 Ć· 7 = 259) | 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 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | 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 1813 a prime number?
No. 1813 = Ć 37, so it is divisible by 7.
What are the factors of 1813?
1, 7, 37, 49, 259, 1813.
What is 1813 in binary?
11100010101 (hexadecimal 715, octal 3425).
What is the square root of 1813?
About 42.5793, exactly 7ā37.
What is 1813 in Roman numerals?
MDCCCXIII.
Is 1813 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 1813?
It is a composite number with 6 divisors.