The number 28489
28489 is a composite number with 4 divisors. Its prime factorisation is 31 × 919. Divisors (4): 1, 31, 919, 28489.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 28489: a Harshad number: divisible by its digit sum 31; a semiprime: 31 × 919, the product of two primes.
- 2
28489 is composite. Its prime factorisation is
- 3
The divisors add up to 29440; without 28489 itself that is 951, so 28489 is deficient (951 is less than 28489). Euler's totient φ(28489) = 27540 numbers up to 28489 share no factor with it.
- 4
The digits of 28489 add up to 31, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 103 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28489 = 31 \times 919 \]
28489 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 29440 |
| Euler totient φ(n) | 27540 |
| Square | 811623121 |
| Cube | 23122331094169 |
| Square root | 168.786848 |
| Digit sum / digital root | 31 / 4 |
| Collatz steps to 1 | 103 |
| Scientific notation | 2.8489 × |
28489 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand four hundred and eighty-nine |
| Binary (base 2) | 110111101001001 |
| Octal (base 8) | 67511 |
| Hexadecimal (base 16) | 6F49 |
| Base 3 | 1110002011 |
| As time | 28489 seconds = 7 h 54 min 49 s |
Is 28489 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 6) | 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 4) | 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 10) | 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 28489 a prime number?
No. 28489 = 31 × 919, so it is divisible by 31.
What are the factors of 28489?
1, 31, 919, 28489.
What is 28489 in binary?
110111101001001 (hexadecimal 6F49, octal 67511).
What is the square root of 28489?
About 168.7868.
Is 28489 divisible by 3?
No. Its digits add up to 31, which is not a multiple of 3.
What is special about the number 28489?
28489 is a Harshad number: divisible by its digit sum 31; a semiprime: 31 × 919, the product of two primes.