666818065 has 8 divisors (see below), whose sum is σ = 810311040. Its totient is φ = 526701552.

The previous prime is 666818063. The next prime is 666818077. The reversal of 666818065 is 560818666.

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 666818065 - 2¹ = 666818063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666818063) 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 7 ways as a sum of consecutive naturals, for example, 843679 + ... + 844468.

It is an arithmetic number, because the mean of its divisors is an integer number (101288880).

Almost surely, 2^666818065 is an apocalyptic number.

It is an amenable number.

666818065 is a deficient number, since it is larger than the sum of its proper divisors (143492975).

666818065 is a wasteful number, since it uses less digits than its factorization.

666818065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1688231.

The product of its (nonzero) digits is 414720, while the sum is 46.

The square root of 666818065 is about 25822.8206244012. The cubic root of 666818065 is about 873.6465890442.

The spelling of 666818065 in words is "six hundred sixty-six million, eight hundred eighteen thousand, sixty-five".