27499 is a member of OEIS A363965: binary palindromic numbers whose digit sum and aliquot sum are also binary palindromic. Here the palindromes are 110101101101011 (27499), 11111 (digit sum) and 101101101 (aliquot sum). The sequence can be generated as follows:

INPUT

L=[]

for n in [1..40000]:

  D=sum(n.digits())

  A=sigma(n)-n

  N=n.str(base=2)

  X=A.str(base=2)

  Y=D.str(base=2)

  if str(N)==str(N) [::-1]:

    if str(X)==str(X) [::-1]:

      if str(Y)==str(Y) [::-1]:

        L.append(n)

print(L)

OUTPUT

[1, 3, 5, 7, 45, 313, 403, 1501, 1619, 2193, 2661, 5349, 11997, 21477, 21653, 24029, 27499]

27499 is a semiprime that contains 7 as a digit of the number itself and also of both factors. See Bespoken for Sequences entry. The semiprimes with this property from 27499 to 40000 are as follows:

27499, 27589, 27629, 27659, 27667, 27769, 27787, 27829, 28157, 28187, 28997, 29257, 29467, 29597, 29779, 29897, 30079, 30379, 30749, 30779, 30967, 31709, 31739, 31807, 32179, 32447, 32711, 32753, 32947, 33047, 33157, 33257, 33719, 33779, 33793, 34097, 34417, 34577, 34733, 34769, 34967, 35179, 35297, 35479, 35579, 35749, 35767, 35779, 35927, 36197, 36379, 36763, 37043, 37079, 37127, 37129, 37319, 37429, 37459, 37519, 37709, 37841, 37849, 37909, 37919, 37949, 38257, 38297, 38473, 38837, 38879, 39271, 39547, 39907, 39977

27499 is a cyclic, Duffinian and self number.

27499 can be rendered as a digit equation as follows:

2 = 7 - 4 - 9 / 9