181

181 is prime, and a palindromic,strobogrammatic, and dihedral number in decimal. 181 is a Chen prime. 181 is a twin prime with 179,equal to the sum of five consecutive prime numbers: 29 + 31 + 37 + 41 + 43. 181 is the difference of two consecutive square numbers 912 – 902, as well as the sum of two consecutive squares: 92 + 102.