 111 (another Prime Pages' Curiosity) Curios: Curios Search:   Participate:  GIMPS has discovered a new largest known prime number: 282589933-1 (24,862,048 digits) The magic constant for the smallest magic square composed only of prime numbers if 1 were counted as a prime. 111322 + 322111 is prime. [Kulsha] The number of consecutive composites that follow the prime 370261, the first run of more than 100. Nayan Hajratwala's home computer, a 350 MHz IBM Aptiva, used 111 days of idle time to find the thirty-eighth Mersenne prime. 1112 + 2 is prime. 111 equals the sum of 2 + 3 + 4 + ... + 17 minus the sum of primes less than 17. [Trotter] 10^(2*55)+111*10^(55-1)+1 is a palindromic prime with 111 digits and 111 as the "center nut" of the number. [Fougeron] 111*10^100+1 is the smallest prime which is one more than a multiple of googol. [Wu] The smallest palindromic number whose English names contain a prime number of letters. [Russo] The smallest multi-digit palindromic number n such that the number of primes below n^2 does not exceed n times the number of primes below n. [Russo] The smallest palindromic number n such that the sum of its digits is a prime factor. [Russo] 111 x 2111 - 111 - 2111 is prime. [Noll] The smallest tetradic semiprime. Note that this number contains the smallest tetradic prime. [Capelle] (There are 8 curios for this number that have not yet been approved by an editor.) Prime Curios! © 2000-2019 (all rights reserved)  privacy statement