What is the lowest prime number 1,2,3,4

Hey there, well we know a prime number must have exactly two factors, which is 1 and its self. 2 is the lowest prime number because because the common divisors for 2 is 1 and 2. Therefore, 2 is the lowest prime number.

Additive primes

Primes such that the sum of digits is a prime.

2, 3, 5, 7, 11, 23, 29, 41, 43, 47, 61, 67, 83, 89, 101, 113, 131