27591 is a member of OEIS A123782: number of ways to build a contiguous building with n LEGO blocks of size 1 x 4 on top of a fixed block of the same size, here n = 3. See blog post LEGO Mathematics.

The progression is: 23, 679, 27591, 1227556, 59212274, 2990304700, 156407426393

27591 is a sphenic number.

27591 can be rendered as a digit equation:

-2 + 7 + 5 = 9 + 1