166565511663 has 16 divisors (see below), whose sum is σ = 233956504320. Its totient is φ = 105118114176.

The previous prime is 166565511661. The next prime is 166565511683. The reversal of 166565511663 is 366115565661.

It is not a de Polignac number, because 166565511663 - 2¹ = 166565511661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166565511661) 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, 1052595 + ... + 1200452.

It is an arithmetic number, because the mean of its divisors is an integer number (14622281520).

Almost surely, 2^166565511663 is an apocalyptic number.

166565511663 is a deficient number, since it is larger than the sum of its proper divisors (67390992657).

166565511663 is a wasteful number, since it uses less digits than its factorization.

166565511663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2254366.

The product of its digits is 2916000, while the sum is 51.

The spelling of 166565511663 in words is "one hundred sixty-six billion, five hundred sixty-five million, five hundred eleven thousand, six hundred sixty-three".