The number 28997
28997 is a composite number with 4 divisors. Its prime factorisation is 107 × 271. Divisors (4): 1, 107, 271, 28997.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 28997: a semiprime: 107 × 271, the product of two primes.
- 2
28997 is composite. Its prime factorisation is
- 3
The divisors add up to 29376; without 28997 itself that is 379, so 28997 is deficient (379 is less than 28997). Euler's totient φ(28997) = 28620 numbers up to 28997 share no factor with it.
- 4
The digits of 28997 add up to 35, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 72 steps to reach 1.
LaTeX source of the formulas on this page
\[ 28997 = 107 \times 271 \]
28997 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 29376 |
| Euler totient φ(n) | 28620 |
| Square | 840826009 |
| Cube | 24381431782973 |
| Square root | 170.285055 |
| Digit sum / digital root | 35 / 8 |
| Collatz steps to 1 | 72 |
| Scientific notation | 2.8997 × |
28997 in other forms
| Form | Value |
|---|---|
| In words | twenty-eight thousand nine hundred and ninety-seven |
| Binary (base 2) | 111000101000101 |
| Octal (base 8) | 70505 |
| Hexadecimal (base 16) | 7145 |
| Base 3 | 1110202222 |
| As time | 28997 seconds = 8 h 3 min 17 s |
Is 28997 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 2) | 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 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | 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 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 28997 a prime number?
No. 28997 = 107 × 271, so it is divisible by 107.
What are the factors of 28997?
1, 107, 271, 28997.
What is 28997 in binary?
111000101000101 (hexadecimal 7145, octal 70505).
What is the square root of 28997?
About 170.2851.
Is 28997 divisible by 3?
No. Its digits add up to 35, which is not a multiple of 3.
What is special about the number 28997?
28997 is a semiprime: 107 × 271, the product of two primes.