19

This number is a prime.

Single Curio View: (Seek other curios for this number)

The following are primes: 19, 109, 1009, 10009. No other digit can replace the 9 and yield four primes. [This is the first entry listed as a "Prime Curio" in the book NUMBERS: Fun & Facts by J. Newton Friend; Charles Scribner's Sons, New York (1954); Library of Congress Catalog No. 54-8690, p. 45.]

Submitted: 2006-08-17 22:29:36; Last Modified: 2023-10-14 21:28:15.