Is the 26th power of 2 minus 1 prime?

Is the 26th power of 2 minus 1 prime?

The 26th power of 2 minus 1
=(2^13-1)(2^13+1)
2 ^ 26-1 must have two factors greater than 1
SO 2 ^ 26-1 is a composite number

Is the 52nd power of 2-1 and the 90th power of 3 + 1 prime or composite

2^52 - 1 = (2^26 + 1)(2^26 - 1)
3^90 + 1 = (3^30)^3 + 1^3 = (3^30 + 1)(3^60 - 3^30 + 1)
So these two are not prime numbers, they are composite numbers

When 23 times a natural number, if the product is prime, it should be multiplied by (). The product is a composite number, it should be multiplied by (). The product is odd. If the product can be divided by 3, it should be multiplied by ()

23 times a natural number:
The product is prime and should be multiplied by (1)
The product is a composite number and should be multiplied by (a natural number greater than 1)
The product is odd, multiplied by (odd)
The product can be divided by 3 and should be multiplied by (a multiple of 3)