emirp A prime number that becomes a different prime number when its digits are reversed ("emirp" is "prime" spelled backwards). The first twenty emirps are 13, 17, 31, 37, 71, 73, 79, 97, 107, 113, 149, 157, 167, 179, 199, 311, 337, 347, 359, and 389. Compare with a palindromic prime (see palindromic number), which gives the same prime when reversed. Related category PRIME NUMBERS Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |