The number 30021
30021 is a composite number with 4 divisors. Its prime factorisation is 3 × 10007. Divisors (4): 1, 3, 10007, 30021.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 30021: a semiprime: 3 × 10007, the product of two primes.
- 2
30021 is composite. Its prime factorisation is
- 3
The divisors add up to 40032; without 30021 itself that is 10011, so 30021 is deficient (10011 is less than 30021). Euler's totient φ(30021) = 20012 numbers up to 30021 share no factor with it.
- 4
The digits of 30021 add up to 6, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 178 steps to reach 1.
LaTeX source of the formulas on this page
\[ 30021 = 3 \times 10007 \]
30021 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 40032 |
| Euler totient φ(n) | 20012 |
| Square | 901260441 |
| Cube | 27056739699261 |
| Square root | 173.265692 |
| Digit sum / digital root | 6 / 6 |
| Collatz steps to 1 | 178 |
| Scientific notation | 3.0021 × |
30021 in other forms
| Form | Value |
|---|---|
| In words | thirty thousand and twenty-one |
| Binary (base 2) | 111010101000101 |
| Octal (base 8) | 72505 |
| Hexadecimal (base 16) | 7545 |
| Base 3 | 1112011220 |
| As time | 30021 seconds = 8 h 20 min 21 s |
Is 30021 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 (30021 ÷ 3 = 10007) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 6) | 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 2) | 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 30021 a prime number?
No. 30021 = 3 × 10007, so it is divisible by 3.
What are the factors of 30021?
1, 3, 10007, 30021.
What is 30021 in binary?
111010101000101 (hexadecimal 7545, octal 72505).
What is the square root of 30021?
About 173.2657.
Is 30021 divisible by 3?
Yes. Its digits add up to 6, a multiple of 3.
What is special about the number 30021?
30021 is a semiprime: 3 × 10007, the product of two primes.