27428 is a product of a power of 2 and a 4k+1 prime. Therefore it can be expressed as a sum of two squares in one way only viz. 122^2 + 112^2.

27428 is a member of OEIS A005710: a(n) = a(n-1) + a(n-8), with a(i) = 1 for i = 0 ... 7. The sequence begins:

1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 14, 18, 23, 29, 36, 44, 53, 64, 78, 96, 119, 148, 184, 228, 281, 345, 423, 519, 638, 786, 970, 1198, 1479, 1824, 2247, 2766, 3404, 4190, 5160, 6358, 7837, 9661, 11908, 14674, 18078, 22268, 27428, 33786, 41623

27248 can be rendered as a digit equation as follows:

2 * 7 - 2 = 4 + 8

27428 stabilises after about 110 generations to a single blinker and an assortment of still life shapes.