166855171689 has 6 divisors (see below), whose sum is σ = 241013025786. Its totient is φ = 111236781120.

The previous prime is 166855171633. The next prime is 166855171727. The reversal of 166855171689 is 986171558661.

166855171689 is a `hidden beast` number, since 1 + 6 + 6 + 8 + 551 + 71 + 6 + 8 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 129222275625 + 37632896064 = 359475^2 + 193992^2 .

It is not a de Polignac number, because 166855171689 - 2¹¹ = 166855169641 is a prime.

It is a super-2 number, since 2×166855171689² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (166855171789) 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 5 ways as a sum of consecutive naturals, for example, 9269731752 + ... + 9269731769.

It is an arithmetic number, because the mean of its divisors is an integer number (40168837631).

Almost surely, 2^166855171689 is an apocalyptic number.

It is an amenable number.

166855171689 is a deficient number, since it is larger than the sum of its proper divisors (74157854097).

166855171689 is a wasteful number, since it uses less digits than its factorization.

166855171689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18539463527 (or 18539463524 counting only the distinct ones).

The product of its digits is 21772800, while the sum is 63.

The spelling of 166855171689 in words is "one hundred sixty-six billion, eight hundred fifty-five million, one hundred seventy-one thousand, six hundred eighty-nine".