The number 21033
21033 is a composite number with 16 divisors. Its prime factorisation is × 19 × 41. Divisors (16): 1, 3, 9, 19, 27, 41, 57, 123, 171, 369, 513, 779, 1107, 2337, 7011, 21033.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21033: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 9.
- 2
21033 is composite. Its prime factorisation is
- 3
The divisors add up to 33600; without 21033 itself that is 12567, so 21033 is deficient (12567 is less than 21033). Euler's totient φ(21033) = 12960 numbers up to 21033 share no factor with it.
- 4
The digits of 21033 add up to 9, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 87 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21033 = 3^{3} \times 19 \times 41 \]21033 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 33600 |
| Euler totient φ(n) | 12960 |
| Square | 442387089 |
| Cube | 9304727642937 |
| Square root | 145.027584 (= 3√2337) |
| Digit sum / digital root | 9 / 9 |
| Collatz steps to 1 | 87 |
| Scientific notation | 2.1033 × |
21033 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand and thirty-three |
| Binary (base 2) | 101001000101001 |
| Octal (base 8) | 51051 |
| Hexadecimal (base 16) | 5229 |
| Base 3 | 1001212000 |
| As time | 21033 seconds = 5 h 50 min 33 s |
Is 21033 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 (21033 ÷ 3 = 7011) | 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 3) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (21033 ÷ 9 = 2337) | 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 1) | 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 21033 a prime number?
No. 21033 = × 19 × 41, so it is divisible by 3.
What are the factors of 21033?
1, 3, 9, 19, 27, 41, 57, 123, 171, 369, 513, 779, 1107, 2337, 7011, 21033.
What is 21033 in binary?
101001000101001 (hexadecimal 5229, octal 51051).
What is the square root of 21033?
About 145.0276, exactly 3√2337.
Is 21033 divisible by 3?
Yes. Its digits add up to 9, a multiple of 3.
What is special about the number 21033?
21033 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 9.