11563660661 has 24 divisors (see below), whose sum is σ = 14768291520. Its totient is φ = 8837652096.

The previous prime is 11563660643. The next prime is 11563660673. The reversal of 11563660661 is 16606636511.

It is not a de Polignac number, because 11563660661 - 2⁶ = 11563660597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11563660601) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 91631 + ... + 177548.

It is an arithmetic number, because the mean of its divisors is an integer number (615345480).

Almost surely, 2^11563660661 is an apocalyptic number.

It is an amenable number.

11563660661 is a deficient number, since it is larger than the sum of its proper divisors (3204630859).

11563660661 is a wasteful number, since it uses less digits than its factorization.

11563660661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269241 (or 269222 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 41.

The spelling of 11563660661 in words is "eleven billion, five hundred sixty-three million, six hundred sixty thousand, six hundred sixty-one".