The number 13129
13129 is a composite number with 4 divisors. Its prime factorisation is 19 × 691. Divisors (4): 1, 19, 691, 13129.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 13129: a semiprime: 19 × 691, the product of two primes.
- 2
13129 is composite. Its prime factorisation is
- 3
The divisors add up to 13840; without 13129 itself that is 711, so 13129 is deficient (711 is less than 13129). Euler's totient φ(13129) = 12420 numbers up to 13129 share no factor with it.
- 4
The digits of 13129 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13129 = 19 \times 691 \]
13129 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 13840 |
| Euler totient φ(n) | 12420 |
| Square | 172370641 |
| Cube | 2263054145689 |
| Square root | 114.581848 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 76 |
| Scientific notation | 1.3129 × |
13129 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand one hundred and twenty-nine |
| Binary (base 2) | 11001101001001 |
| Octal (base 8) | 31511 |
| Hexadecimal (base 16) | 3349 |
| Base 3 | 200000021 |
| As time | 13129 seconds = 3 h 38 min 49 s |
Is 13129 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 4) | 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 4) | 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 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | 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 13129 a prime number?
No. 13129 = 19 × 691, so it is divisible by 19.
What are the factors of 13129?
1, 19, 691, 13129.
What is 13129 in binary?
11001101001001 (hexadecimal 3349, octal 31511).
What is the square root of 13129?
About 114.5818.
Is 13129 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 13129?
13129 is a semiprime: 19 × 691, the product of two primes.