Primes / Is 61 prime?

Is 61 a Prime Number?

Yes

61 is prime: for 61, testing every prime up to √61 ≈ 7.8 (namely 2, 3, 5, 7) finds no divisor. 61 sits between primes 59 and 67, 2 below and 6 above. 61 shares no factor with 2-12; 61's divisors start beyond that range. 61 is odd, digit sum 7 for 61, digital root 7 for 61. 61 has 5 primes within 10 of 61.