11566211211566 has 16 divisors (see below), whose sum is σ = 18982689251760. Its totient is φ = 5241768228480.

The previous prime is 11566211211553. The next prime is 11566211211571. The reversal of 11566211211566 is 66511211266511.

It is a happy number.

11566211211566 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×11566211211566² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 780017621 + ... + 780032448.

It is an arithmetic number, because the mean of its divisors is an integer number (1186418078235).

Almost surely, 2^{11566211211566} is an apocalyptic number.

11566211211566 is a deficient number, since it is larger than the sum of its proper divisors (7416478040194).

11566211211566 is a wasteful number, since it uses less digits than its factorization.

11566211211566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1560050419.

The product of its digits is 129600, while the sum is 44.

Subtracting 11566211211566 from its reverse (66511211266511), we obtain a palindrome (54945000054945).

The spelling of 11566211211566 in words is "eleven trillion, five hundred sixty-six billion, two hundred eleven million, two hundred eleven thousand, five hundred sixty-six".