The number 28243
28243 is a composite number with 4 divisors. Its prime factorisation is 61 × 463. Divisors (4): 1, 61, 463, 28243.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 28243: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 61 × 463, the product of two primes.
- 2
28243 is composite. Its prime factorisation is
- 3
The divisors add up to 28768; without 28243 itself that is 525, so 28243 is deficient (525 is less than 28243). Euler's totient φ(28243) = 27720 numbers up to 28243 share no factor with it.
- 4
The digits of 28243 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 152 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28243 = 61 \times 463 \]
28243 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 28768 |
| Euler totient φ(n) | 27720 |
| Square | 797667049 |
| Cube | 22528510464907 |
| Square root | 168.056538 |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 152 |
| Scientific notation | 2.8243 × |
28243 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand two hundred and forty-three |
| Binary (base 2) | 110111001010011 |
| Octal (base 8) | 67123 |
| Hexadecimal (base 16) | 6E53 |
| Base 3 | 1102202001 |
| As time | 28243 seconds = 7 h 50 min 43 s |
Is 28243 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 3) | 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 1) | 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 3) | 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 3) | 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 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 28243 a prime number?
No. 28243 = 61 × 463, so it is divisible by 61.
What are the factors of 28243?
1, 61, 463, 28243.
What is 28243 in binary?
110111001010011 (hexadecimal 6E53, octal 67123).
What is the square root of 28243?
About 168.0565.
Is 28243 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 28243?
28243 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 61 × 463, the product of two primes.