2101247

This number is a prime.

2101247 and 2101249 are the first twin prime pair of the type (2^n+2^R(n)-1, 2^n+2^R(n)+1), where R(n) is the reversal of n, (case n=12). Note that the sums of their digits are another twin prime pair. Note also, that (n, R(n)) are the only pair of double-digit numbers with the above property. [Loungrides]