The number 13021
13021 is a composite number with 4 divisors. Its prime factorisation is 29 × 449. Divisors (4): 1, 29, 449, 13021.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 13021: a semiprime: 29 × 449, the product of two primes.
- 2
13021 is composite. Its prime factorisation is
- 3
The divisors add up to 13500; without 13021 itself that is 479, so 13021 is deficient (479 is less than 13021). Euler's totient φ(13021) = 12544 numbers up to 13021 share no factor with it.
- 4
The digits of 13021 add up to 7, 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
\[ 13021 = 29 \times 449 \]
13021 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 13500 |
| Euler totient φ(n) | 12544 |
| Square | 169546441 |
| Cube | 2207664208261 |
| Square root | 114.109596 |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 76 |
| Scientific notation | 1.3021 × |
13021 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand and twenty-one |
| Binary (base 2) | 11001011011101 |
| Octal (base 8) | 31335 |
| Hexadecimal (base 16) | 32DD |
| Base 3 | 122212021 |
| As time | 13021 seconds = 3 h 37 min 1 s |
Is 13021 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 1) | 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 5) | 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 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 8) | 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 13021 a prime number?
No. 13021 = 29 × 449, so it is divisible by 29.
What are the factors of 13021?
1, 29, 449, 13021.
What is 13021 in binary?
11001011011101 (hexadecimal 32DD, octal 31335).
What is the square root of 13021?
About 114.1096.
Is 13021 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 13021?
13021 is a semiprime: 29 × 449, the product of two primes.