166866870181 has 16 divisors (see below), whose sum is σ = 182904471360. Its totient is φ = 150974449920.

The previous prime is 166866870161. The next prime is 166866870187. The reversal of 166866870181 is 181078668661.

It is a cyclic number.

It is not a de Polignac number, because 166866870181 - 2⁹ = 166866869669 is a prime.

It is a super-2 number, since 2×166866870181² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166866870187) 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, 7048941 + ... + 7072573.

It is an arithmetic number, because the mean of its divisors is an integer number (11431529460).

Almost surely, 2^166866870181 is an apocalyptic number.

166866870181 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166866870181 is a deficient number, since it is larger than the sum of its proper divisors (16037601179).

166866870181 is a wasteful number, since it uses less digits than its factorization.

166866870181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26676.

The product of its (nonzero) digits is 4644864, while the sum is 58.

The spelling of 166866870181 in words is "one hundred sixty-six billion, eight hundred sixty-six million, eight hundred seventy thousand, one hundred eighty-one".