27668 is product of a power of 2 and a 4k+1 prime and so it can be expressed as a sum of two square in one way only viz. 52^2 + 158^2.

27668 is a member of OEIS A097545: numerators in the progressive Farey fraction approximations to pi, namely 27668/8807.

The sequence from 27668 to 40000 runs:

27668, 28023, 28378, 28733, 29088, 29443, 29798, 30153, 30508, 30863, 31218, 31573, 31928, 32283, 32638, 32993, 33348, 33703, 34058, 34413, 34768, 35123, 35478, 35833, 36188, 36543, 36898, 37253, 37608, 37963, 38318, 38673, 39028, 39383, 39738,

27668 is a self and untouchable number.

27668 can be rendered as a digital equation as follows:

2 + 7 = 6 / 6 + 8