 49 (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 composite number whose digits are composite such that the concatenated factors of either digit with the remaining digit(s) is prime. [Rivera] The first 49 digits after the decimal point in e = 2.718... form a prime. [Honaker] The largest prime square which is greater than the product of all lesser primes. [Murthy] The smallest semiprime whose sum of divisors is also a semiprime. [Gupta] phi(49)*49^49 + 1 is prime. The reversal of 49 has the same property. [Firoozbakht] The smallest square that is the sum of three consecutive primes. [Silva] The smallest prime square that is the sum of consecutive composite numbers in three ways, i.e., 24+25 = 15+16+18 = 4+6+8+9+10+12 = 7^2. [Loungrides] 100^49 + 49 is the largest non-titanic prime of form 100^n + n. [Loungrides] (There are 10 curios for this number that have not yet been approved by an editor.) Prime Curios! © 2000-2020 (all rights reserved)  privacy statement