 121 (another Prime Pages' Curiosity) Curios: Curios Search:   Participate:  GIMPS has discovered a new largest known prime number: 282589933-1 (24,862,048 digits) Every number greater than 121 is the sum of distinct primes of the form 4n + 1. [Wells] The smallest palindromic composite such that some permutation of digits is prime. 121 is the only odd palindromic square with an odd number of digits that is divisible by a palindromic prime number with an even number of digits. [Luhn] A palindrome whose prime factors are palindromic. [Russo] 121 can be expressed as the sum of a prime and its reversal for exactly three distinct primes. [Patterson] The smallest three-digit number such that the sum of the values that result by placing the exponentation symbol (^) between any two consecutive digits is prime (i.e., 1^21+12^1 is prime.) [Opao] 121, 143, 169, and 187 are the first and possibly only four consecutive brilliant numbers whose reverses are also brilliant numbers. [Gaydos] (There are 2 curios for this number that have not yet been approved by an editor.) Prime Curios! © 2000-2020 (all rights reserved)  privacy statement