11566561655 has 16 divisors (see below), whose sum is σ = 15800016384. Its totient is φ = 8046302880.

The previous prime is 11566561639. The next prime is 11566561661. The reversal of 11566561655 is 55616566511.

It is not a de Polignac number, because 11566561655 - 2⁴ = 11566561639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4570499 + ... + 4573028.

It is an arithmetic number, because the mean of its divisors is an integer number (987501024).

Almost surely, 2^11566561655 is an apocalyptic number.

11566561655 is a deficient number, since it is larger than the sum of its proper divisors (4233454729).

11566561655 is a wasteful number, since it uses less digits than its factorization.

11566561655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9143566.

The product of its digits is 810000, while the sum is 47.

The spelling of 11566561655 in words is "eleven billion, five hundred sixty-six million, five hundred sixty-one thousand, six hundred fifty-five".