An emirp is an integer that, when its digits are written in reverse order, is a prime number. For example, 73 is an emirp because 37 is prime. What is the smallest two-digit prime number that is NOT an emirp?

Guest Apr 4, 2019

#1**0 **

37 and 73 are also part of a smaller sequence. The list contains prime numbers in which every single permutation (including deletion) is prime

SEQUENCE:

2-2

3-3

5-5

7-7

37-37,73,3,7

73-73,37,7,3

There are only these 6 numbers in the list.

Answer to your question (if the second number isn't double-digit): 10

Answer to your question (if the second number is double-digit): 12

creepercraft97T3 Apr 4, 2019

#2**+2 **

I think the smallest prime I can think of that is NOT a emirp itself would be 19.

ElectricPavlov Apr 4, 2019