66178161 has 64 divisors (see below), whose sum is σ = 121651200. Its totient is φ = 34691328.

The previous prime is 66178139. The next prime is 66178181. The reversal of 66178161 is 16187166.

It is not a de Polignac number, because 66178161 - 2¹¹ = 66176113 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66178181) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 137920 + ... + 138398.

It is an arithmetic number, because the mean of its divisors is an integer number (1900800).

Almost surely, 2^66178161 is an apocalyptic number.

It is an amenable number.

66178161 is a deficient number, since it is larger than the sum of its proper divisors (55473039).

66178161 is a wasteful number, since it uses less digits than its factorization.

66178161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555 (or 549 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 66178161 is about 8134.9960663789. The cubic root of 66178161 is about 404.4873073565.

The spelling of 66178161 in words is "sixty-six million, one hundred seventy-eight thousand, one hundred sixty-one".