39
(another Prime Pages' Curiosity)
Prime Curios!
Curios: Curios Search:
 
Participate:
+ 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]

+ 100000^39 - 39 is prime. [Firoozbakht]

+ 39 = 3*9 + pi(39) [Firoozbakht]

+ pi(39) = 3 + 9. [Gupta]



Prime Curios! © 1999-2009 (all rights reserved)