Numbers divisible by 1 & number itself are called prime numbers. These numbers also have the property to be odd numbers.
Prime factorization
That's called the prime factorization.
Prime factorization of 27 = 3x3x3
2x2x2x3
2x2x3x5
2x2x3x3x3
You can't write that as the sum of two prime numbers. Note: Goldbach's Conjecture (for expressing numbers as the sum of two prime numbers) applies to EVEN numbers.
In the same way as you would write any integer.
2x2x2x2x3x3=144
2x21x11
fdsgfhgdfhgdf
Since there is an infinite set of prime numbers the answer would be infinity.