The number 13105
13105 is a composite number with 4 divisors. Its prime factorisation is 5 × 2621. Divisors (4): 1, 5, 2621, 13105.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 13105: a semiprime: 5 × 2621, the product of two primes.
- 2
13105 is composite. Its prime factorisation is
- 3
The divisors add up to 15732; without 13105 itself that is 2627, so 13105 is deficient (2627 is less than 13105). Euler's totient φ(13105) = 10480 numbers up to 13105 share no factor with it.
- 4
The digits of 13105 add up to 10, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 138 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13105 = 5 \times 2621 \]
13105 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 15732 |
| Euler totient φ(n) | 10480 |
| Square | 171741025 |
| Cube | 2250666132625 |
| Square root | 114.477072 |
| Digit sum / digital root | 10 / 1 |
| Collatz steps to 1 | 138 |
| Scientific notation | 1.3105 × |
13105 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand one hundred and five |
| Binary (base 2) | 11001100110001 |
| Octal (base 8) | 31461 |
| Hexadecimal (base 16) | 3331 |
| Base 3 | 122222101 |
| As time | 13105 seconds = 3 h 38 min 25 s |
Is 13105 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 | Yes (13105 ÷ 5 = 2621) | 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 | No (remainder 1) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 13105 a prime number?
No. 13105 = 5 × 2621, so it is divisible by 5.
What are the factors of 13105?
1, 5, 2621, 13105.
What is 13105 in binary?
11001100110001 (hexadecimal 3331, octal 31461).
What is the square root of 13105?
About 114.4771.
Is 13105 divisible by 3?
No. Its digits add up to 10, which is not a multiple of 3.
What is special about the number 13105?
13105 is a semiprime: 5 × 2621, the product of two primes.