The number 9813
9813 is a composite number with 4 divisors. Its prime factorisation is 3 × 3271. Divisors (4): 1, 3, 3271, 9813.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 9813: a semiprime: 3 × 3271, the product of two primes.
- 2
9813 is composite. Its prime factorisation is
- 3
The divisors add up to 13088; without 9813 itself that is 3275, so 9813 is deficient (3275 is less than 9813). Euler's totient φ(9813) = 6540 numbers up to 9813 share no factor with it.
- 4
The digits of 9813 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 42 steps to reach 1.
LaTeX source of the formulas on this page
\[ 9813 = 3 \times 3271 \]
9813 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 13088 |
| Euler totient φ(n) | 6540 |
| Square | 96294969 |
| Cube | 944942530797 |
| Square root | 99.060588 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 42 |
| Scientific notation | 9.813 × |
9813 in other forms
| Form | Value |
|---|---|
| In words | nine thousand eight hundred and thirteen |
| Binary (base 2) | 10011001010101 |
| Octal (base 8) | 23125 |
| Hexadecimal (base 16) | 2655 |
| Base 3 | 111110110 |
| As time | 9813 seconds = 2 h 43 min 33 s |
Is 9813 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 (9813 ÷ 3 = 3271) | 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 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | 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 1) | 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 9813 a prime number?
No. 9813 = 3 × 3271, so it is divisible by 3.
What are the factors of 9813?
1, 3, 3271, 9813.
What is 9813 in binary?
10011001010101 (hexadecimal 2655, octal 23125).
What is the square root of 9813?
About 99.0606.
Is 9813 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 9813?
9813 is a semiprime: 3 × 3271, the product of two primes.