It is 43 because 43 is a Prime number
43 is already prime. No factorization.
43 is already prime.
43 is already prime.
43 is already prime.
43 is already prime; no factorization required.
43 is already a prime number.
43 is prime; no factorization.
You don't. 43 is already prime.
The prime factorization of 129= 43 times 3
The prime factorization of 129 is 3 x 43.
19, 43 and 53 are already prime.
None. 43 is a prime number.