Primes / Is 43 prime?

Is 43 a Prime Number?

Yes

43 is prime: for 43, testing every prime up to √43 ≈ 6.6 (namely 2, 3, 5) finds no divisor. 43 sits between primes 41 and 47, 2 below and 4 above. 43 shares no factor with 2-12; 43's divisors start beyond that range. 43 is odd, digit sum 7 for 43, digital root 7 for 43. 43 has 5 primes within 10 of 43.