66168173816 has 16 divisors (see below), whose sum is σ = 130595080200. Its totient is φ = 31342819104.

The previous prime is 66168173807. The next prime is 66168173849. The reversal of 66168173816 is 61837186166.

It is a super-2 number, since 2×66168173816² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 217658315 + ... + 217658618.

Almost surely, 2^66168173816 is an apocalyptic number.

It is an amenable number.

66168173816 is a deficient number, since it is larger than the sum of its proper divisors (64426906384).

66168173816 is a wasteful number, since it uses less digits than its factorization.

66168173816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435316958 (or 435316954 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 53.

The spelling of 66168173816 in words is "sixty-six billion, one hundred sixty-eight million, one hundred seventy-three thousand, eight hundred sixteen".