556166665506161 has 16 divisors (see below), whose sum is σ = 560195570488320. Its totient is φ = 552149468906880.

The previous prime is 556166665506143. The next prime is 556166665506163. The reversal of 556166665506161 is 161605566661655.

It is a cyclic number.

It is not a de Polignac number, because 556166665506161 - 2¹⁸ = 556166665244017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (556166665506163) 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, 3632316941 + ... + 3632470053.

It is an arithmetic number, because the mean of its divisors is an integer number (35012223155520).

Almost surely, 2^{556166665506161} is an apocalyptic number.

It is an amenable number.

556166665506161 is a deficient number, since it is larger than the sum of its proper divisors (4028904982159).

556166665506161 is a wasteful number, since it uses less digits than its factorization.

556166665506161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191176.

The product of its (nonzero) digits is 174960000, while the sum is 65.

The spelling of 556166665506161 in words is "five hundred fifty-six trillion, one hundred sixty-six billion, six hundred sixty-five million, five hundred six thousand, one hundred sixty-one".