 39 (another Prime Pages' Curiosity) Curios: Curios Search:   Participate:  GIMPS has discovered a new largest known prime number: 282589933-1 (24,862,048 digits) The least composite odd number that is the sum of the primes between its smallest and largest prime factors (39 = 3 * 13 = 3 + 5 + 7 + 11 + 13). [Rivera] Concatenating the 39th row numbers of Pascal's triangle forms a prime. [Rivera] 39 is the smallest positive integer which cannot be formed from the first four primes (used once each), using only the simple operations +, -, *, / and ^. [Hartley] 39 = nextprime(3+9)* ( (3+9)). The two numbers 39 and reversal(nextprime(39)) are the only numbers with this property. [Hasler] The number formed by concatenating the non-prime integers 1 through 39 is the smallest such prime: 1468910121415161820212224252627283032333435363839. [Loungrides] (There are 4 curios for this number that have not yet been approved by an editor.)   To link to this page use /curios/page.php?number_id=406 Prime Curios! © 2000-2020 (all rights reserved)  privacy statement   (This page was generated in 0.0183 seconds.)