166557663866 has 32 divisors (see below), whose sum is σ = 277891499520. Its totient is φ = 74231812800.

The previous prime is 166557663823. The next prime is 166557663869. The reversal of 166557663866 is 668366755661.

166557663866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166557663869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 229655 + ... + 621173.

It is an arithmetic number, because the mean of its divisors is an integer number (8684109360).

Almost surely, 2^166557663866 is an apocalyptic number.

166557663866 is a deficient number, since it is larger than the sum of its proper divisors (111333835654).

166557663866 is a wasteful number, since it uses less digits than its factorization.

166557663866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391910.

The product of its digits is 195955200, while the sum is 65.

The spelling of 166557663866 in words is "one hundred sixty-six billion, five hundred fifty-seven million, six hundred sixty-three thousand, eight hundred sixty-six".