166665800943 has 12 divisors (see below), whose sum is σ = 241295476240. Its totient is φ = 110853925056.

The previous prime is 166665800869. The next prime is 166665800953. The reversal of 166665800943 is 349008566661.

It is not a de Polignac number, because 166665800943 - 2²⁵ = 166632246511 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166665800943.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166665800953) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21379963 + ... + 21387756.

Almost surely, 2^166665800943 is an apocalyptic number.

166665800943 is a deficient number, since it is larger than the sum of its proper divisors (74629675297).

166665800943 is a wasteful number, since it uses less digits than its factorization.

166665800943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42768158 (or 42768155 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 54.

The spelling of 166665800943 in words is "one hundred sixty-six billion, six hundred sixty-five million, eight hundred thousand, nine hundred forty-three".