11365661661 has 24 divisors (see below), whose sum is σ = 16945368480. Its totient is φ = 6756049152.

The previous prime is 11365661653. The next prime is 11365661687. The reversal of 11365661661 is 16616656311.

It is not a de Polignac number, because 11365661661 - 2³ = 11365661653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11365661621) 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, 328506 + ... + 361451.

It is an arithmetic number, because the mean of its divisors is an integer number (706057020).

Almost surely, 2^11365661661 is an apocalyptic number.

It is an amenable number.

11365661661 is a deficient number, since it is larger than the sum of its proper divisors (5579706819).

11365661661 is a wasteful number, since it uses less digits than its factorization.

11365661661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690013 (or 689996 counting only the distinct ones).

The product of its digits is 116640, while the sum is 42.

The spelling of 11365661661 in words is "eleven billion, three hundred sixty-five million, six hundred sixty-one thousand, six hundred sixty-one".