66818065 has 8 divisors (see below), whose sum is σ = 80976168. Its totient is φ = 52924800.

The previous prime is 66818053. The next prime is 66818093. The reversal of 66818065 is 56081866.

It is a happy number.

66818065 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 13571856 + 53246209 = 3684^2 + 7297^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66818065 - 2⁵ = 66818033 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65652 + ... + 66661.

It is an arithmetic number, because the mean of its divisors is an integer number (10122021).

Almost surely, 2^66818065 is an apocalyptic number.

It is an amenable number.

66818065 is a deficient number, since it is larger than the sum of its proper divisors (14158103).

66818065 is a wasteful number, since it uses less digits than its factorization.

66818065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132419.

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 66818065 is about 8174.2317681847. The cubic root of 66818065 is about 405.7868460578.

The spelling of 66818065 in words is "sixty-six million, eight hundred eighteen thousand, sixty-five".