401

401 is a prime number, tetranacci number,Chen prime, prime index prime Eisenstein prime with no imaginary part Sum of seven consecutive primes (43 + 47 + 53 + 59 + 61 + 67 + 71) Sum of nine consecutive primes (29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61) Mertens function returns 0,