27660721605 has 24 divisors (see below), whose sum is σ = 48646297056. Its totient is φ = 13411258080.

The previous prime is 27660721589. The next prime is 27660721661. The reversal of 27660721605 is 50612706672.

It is not a de Polignac number, because 27660721605 - 2⁴ = 27660721589 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7618219 + ... + 7621848.

It is an arithmetic number, because the mean of its divisors is an integer number (2026929044).

Almost surely, 2^27660721605 is an apocalyptic number.

It is an amenable number.

27660721605 is a deficient number, since it is larger than the sum of its proper divisors (20985575451).

27660721605 is a wasteful number, since it uses less digits than its factorization.

27660721605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15240097 (or 15240086 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 42.

The spelling of 27660721605 in words is "twenty-seven billion, six hundred sixty million, seven hundred twenty-one thousand, six hundred five".