27327 is a number that is symmetric about its centre digit, here 27 - 3 - 27. There are 489 such numbers in the range up to 40000. See Bespoken for Sequences entry. Here are the members of the sequence from 27327 to 40000:

27327, 27427, 27527, 27627, 27727, 27827, 27927, 28028, 28128, 28228, 28328, 28428, 28528, 28628, 28728, 28828, 28928, 29029, 29129, 29229, 29329, 29429, 29529, 29629, 29729, 29829, 29929, 30030, 30130, 30230, 30330, 30430, 30530, 30630, 30730, 30830, 30930, 31031, 31131, 31231, 31331, 31431, 31531, 31631, 31731, 31831, 31931, 32032, 32132, 32232, 32332, 32432, 32532, 32632, 32732, 32832, 32932, 33033, 33133, 33233, 33333, 33433, 33533, 33633, 33733, 33833, 33933, 34034, 34134, 34234, 34334, 34434, 34534, 34634, 34734, 34834, 34934, 35035, 35135, 35235, 35335, 35435, 35535, 35635, 35735, 35835, 35935, 36036, 36136, 36236, 36336, 36436, 36536, 36636, 36736, 36836, 36936, 37037, 37137, 37237, 37337, 37437, 37537, 37637, 37737, 37837, 37937, 38038, 38138, 38238, 38338, 38438, 38538, 38638, 38738, 38838, 38938, 39039, 39139, 39239, 39339, 39439, 39539, 39639, 39739, 39839, 39939

27327 is a de Polignac number because none of the positive numbers 27327 - 2^k is a prime.

27327 is a Duffinian number.

27327 is a congruent number.

27327 is a D-number because 2^27327+1 is divisible by 2*27327+1.