No, not all composite numbers are divisible by 2.
A composite number is a positive integer that has more than two factors (i.e., it is not a prime number). While some composite numbers are divisible by 2, others are divisible by different prime numbers, and some are divisible by multiple prime numbers (including and excluding 2).
For example:
- Divisible by 2: 4, 6, 8, 10, 12, 14, 16, etc.
- Not divisible by 2: 9, 15, 21, 25, 27, 33, 35, 49, etc. These are divisible by other prime numbers such as 3, 5, and 7.
A composite number must have a prime factor other than 1 and itself to be composite. If the prime factor is 2, then it is divisible by 2. If the prime factor is anything else, it is not divisible by 2.
For a composite number to be divisible by 2, it must be an even number. Odd composite numbers are never divisible by 2.
| Number | Composite? | Divisible by 2? | Prime Factors |
|---|---|---|---|
| 4 | Yes | Yes | 2 x 2 |
| 6 | Yes | Yes | 2 x 3 |
| 9 | Yes | No | 3 x 3 |
| 15 | Yes | No | 3 x 5 |
| 25 | Yes | No | 5 x 5 |
| 28 | Yes | Yes | 2 x 2 x 7 |
| 33 | Yes | No | 3 x 11 |
As you can see from the table, several composite numbers are not divisible by 2.
In summary, the divisibility of a composite number depends on its specific factors; not all are divisible by 2.
