66408165 has 12 divisors (see below), whose sum is σ = 115107564. Its totient is φ = 35417664.

The previous prime is 66408163. The next prime is 66408187. The reversal of 66408165 is 56180466.

66408165 is a `hidden beast` number, since 6 + 640 + 8 + 1 + 6 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 48692484 + 17715681 = 6978^2 + 4209^2 .

It is not a de Polignac number, because 66408165 - 2¹ = 66408163 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66408161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 737824 + ... + 737913.

It is an arithmetic number, because the mean of its divisors is an integer number (9592297).

Almost surely, 2^66408165 is an apocalyptic number.

It is an amenable number.

66408165 is a deficient number, since it is larger than the sum of its proper divisors (48699399).

66408165 is a wasteful number, since it uses less digits than its factorization.

66408165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1475748 (or 1475745 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 66408165 is about 8149.1205046925. The cubic root of 66408165 is about 404.9553677382.

The spelling of 66408165 in words is "sixty-six million, four hundred eight thousand, one hundred sixty-five".