11665566556611 has 16 divisors (see below), whose sum is σ = 16969821857280. Its totient is φ = 7069321567520.

The previous prime is 11665566556601. The next prime is 11665566556621.

It is a happy number.

11665566556611 is nontrivially palindromic in base 10.

11665566556611 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (11665566556601) and next prime (11665566556621).

It is a cyclic number.

It is not a de Polignac number, because 11665566556611 - 2¹¹ = 11665566554563 is a prime.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (11665566556601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17639640 + ... + 18289013.

It is an arithmetic number, because the mean of its divisors is an integer number (1060613866080).

Almost surely, 2^{11665566556611} is an apocalyptic number.

11665566556611 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11665566556611 is a deficient number, since it is larger than the sum of its proper divisors (5304255300669).

11665566556611 is a wasteful number, since it uses less digits than its factorization.

11665566556611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35938506.

The product of its digits is 29160000, while the sum is 60.

The spelling of 11665566556611 in words is "eleven trillion, six hundred sixty-five billion, five hundred sixty-six million, five hundred fifty-six thousand, six hundred eleven".