11666556505569 has 16 divisors (see below), whose sum is σ = 17781048023040. Its totient is φ = 6665314426320.

The previous prime is 11666556505517. The next prime is 11666556505603. The reversal of 11666556505569 is 96550565566611.

It is not a de Polignac number, because 11666556505569 - 2⁷ = 11666556505441 is a prime.

It is a super-2 number, since 2×11666556505569² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11666556505369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53609289 + ... + 53826470.

It is an arithmetic number, because the mean of its divisors is an integer number (1111315501440).

Almost surely, 2^{11666556505569} is an apocalyptic number.

It is an amenable number.

11666556505569 is a deficient number, since it is larger than the sum of its proper divisors (6114491517471).

11666556505569 is a wasteful number, since it uses less digits than its factorization.

11666556505569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107440940.

The product of its (nonzero) digits is 218700000, while the sum is 66.

The spelling of 11666556505569 in words is "eleven trillion, six hundred sixty-six billion, five hundred fifty-six million, five hundred five thousand, five hundred sixty-nine".