166918586861 has 8 divisors (see below), whose sum is σ = 179942482104. Its totient is φ = 153920977920.

The previous prime is 166918586767. The next prime is 166918586903. The reversal of 166918586861 is 168685819661.

It can be written as a sum of positive squares in 4 ways, for example, as 62545008100 + 104373578761 = 250090^2 + 323069^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166918586861 - 2¹⁴ = 166918570477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166918580861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6558380 + ... + 6583781.

It is an arithmetic number, because the mean of its divisors is an integer number (22492810263).

Almost surely, 2^166918586861 is an apocalyptic number.

It is an amenable number.

166918586861 is a deficient number, since it is larger than the sum of its proper divisors (13023895243).

166918586861 is a wasteful number, since it uses less digits than its factorization.

166918586861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13143151.

The product of its digits is 29859840, while the sum is 65.

The spelling of 166918586861 in words is "one hundred sixty-six billion, nine hundred eighteen million, five hundred eighty-six thousand, eight hundred sixty-one".