27615 is a member of OEIS A124494: numbers k for which 2*k-1, 4*k-1, 8*k-1 and 16*k-1 are primes. The initial members are:

3, 45, 90, 180, 255, 615, 705, 1350, 1770, 3225, 5295, 5775, 5955, 6060, 8580, 9855, 9945, 11175, 13095, 13740, 15195, 21825, 26820, 26925, 27615, 28920, 30075, 30705, 31710, 33375, 35700, 37350, 37665, 41250, 43770, 49185, 50700, 52185, 53640

27615 has a totient (12576) that is a permutation of the digits of the number.

27615 is a katadrome in base 13 : c753 since its digits are strictly decreasing.

27615 is a metadrome in base 16 : 6bdf since its digits are strictly increasing.

27615 is a xenodrome in base 10 as well as bases 9, 11, 13, 14, 15 and 16.

27615 is a composite number one step removed from home prime of 357263.

27615 can be rendered as a digit equation as follows:

-2 + 7 = 6 - 1 ^ 5