241

241 is the larger of the twin primes (239, 241). Twin primes are pairs of primes separated by 2.
241 is a regular prime and a lucky prime. Since 241 = 15 × 24 + 1, it is a Proth prime.
241 is a repdigit in base 15 (111).
241 is the only known Lucas–Wieferich prime to (U, V) = (3, −1).