647 (another Prime Pages' Curiosity)
 Curios: Curios Search:   Participate: GIMPS has discovered a new largest known prime number: 282589933-1 (24,862,048 digits) The smallest prime that may be written as 2a2 - 1, and also as 3b3 - 1. [Hartley] A man described as looking like a plump Moses asked the following questions during a 1987 joint American Mathematical Society/Mathematical Association of America conference in San Antonio, Texas: "What about 647? Is it prime?" (from The Man Who Loved Only Numbers by Paul Hoffman) 647 equals the sum of all two-digit even semiprimes plus one. [Silva] The largest prime whose digits form an acute-angle scalene triangle with prime perimeter. [Loungrides] The largest 3-digit number n such that 3^n-2^n is prime, 3^647-2^647. [Loungrides] The only prime of form p^(p+1)+q^(q+1)-1, where p, q are consecutive primes, i.e., 2^3*3^4-1. [Loungrides] Prime Curios! © 2000-2019 (all rights reserved)  privacy statement   (This page was generated in 0.0367 seconds.)