The number 3813
3813 is a composite number with 8 divisors. Its prime factorisation is 3 × 31 × 41. Divisors (8): 1, 3, 31, 41, 93, 123, 1271, 3813.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
3813 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
3813 is composite. Its prime factorisation is
- 3
The divisors add up to 5376; without 3813 itself that is 1563, so 3813 is deficient (1563 is less than 3813). Euler's totient φ(3813) = 2400 numbers up to 3813 share no factor with it.
- 4
The digits of 3813 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 30 steps to reach 1.
LaTeX source of the formulas on this page
\[ 3813 = 3 \times 31 \times 41 \]
3813 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 5376 |
| Euler totient φ(n) | 2400 |
| Square | 14538969 |
| Cube | 55437088797 |
| Square root | 61.749494 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 30 |
| Scientific notation | 3.813 × |
3813 in other forms
| Form | Value |
|---|---|
| In words | three thousand eight hundred and thirteen |
| Roman numerals | MMMDCCCXIII |
| Binary (base 2) | 111011100101 |
| Octal (base 8) | 7345 |
| Hexadecimal (base 16) | EE5 |
| Base 3 | 12020020 |
| As time | 3813 seconds = 1 h 3 min 33 s |
Is 3813 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 (3813 ÷ 3 = 1271) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 6) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 3813 a prime number?
No. 3813 = 3 × 31 × 41, so it is divisible by 3.
What are the factors of 3813?
1, 3, 31, 41, 93, 123, 1271, 3813.
What is 3813 in binary?
111011100101 (hexadecimal EE5, octal 7345).
What is the square root of 3813?
About 61.7495.
What is 3813 in Roman numerals?
MMMDCCCXIII.
Is 3813 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 3813?
It is a composite number with 8 divisors.