27641 is a member of OEIS A108540: Golden semiprimes: a(n)=p*q and abs(p*phi-q)<1, where phi = golden ratio = (1+sqrt(5))/2. See blog post Golden Semiprimes and More About Golden Semiprimes.

27641 is a cyclic and Duffinian number.

27641 is a nialpdrome in base 13 : c773.

27641 can be rendered as a digit equation as follows:

2 + 7 - 6 = 4 - 1