The number 13643
13643 is a composite number with 4 divisors. Its prime factorisation is 7 × 1949. Divisors (4): 1, 7, 1949, 13643.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 13643: a semiprime: 7 × 1949, the product of two primes.
- 2
13643 is composite. Its prime factorisation is
- 3
The divisors add up to 15600; without 13643 itself that is 1957, so 13643 is deficient (1957 is less than 13643). Euler's totient φ(13643) = 11688 numbers up to 13643 share no factor with it.
- 4
The digits of 13643 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 138 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13643 = 7 \times 1949 \]
13643 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 15600 |
| Euler totient φ(n) | 11688 |
| Square | 186131449 |
| Cube | 2539391358707 |
| Square root | 116.803253 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 138 |
| Scientific notation | 1.3643 × |
13643 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand six hundred and forty-three |
| Binary (base 2) | 11010101001011 |
| Octal (base 8) | 32513 |
| Hexadecimal (base 16) | 354B |
| Base 3 | 200201022 |
| As time | 13643 seconds = 3 h 47 min 23 s |
Is 13643 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 2) | 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 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (13643 ÷ 7 = 1949) | 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 8) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 13643 a prime number?
No. 13643 = 7 × 1949, so it is divisible by 7.
What are the factors of 13643?
1, 7, 1949, 13643.
What is 13643 in binary?
11010101001011 (hexadecimal 354B, octal 32513).
What is the square root of 13643?
About 116.8033.
Is 13643 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 13643?
13643 is a semiprime: 7 × 1949, the product of two primes.