320640066 has 32 divisors (see below), whose sum is σ = 737107200. Its totient is φ = 103194000.

The previous prime is 320640059. The next prime is 320640097. The reversal of 320640066 is 660046023.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100810 + ... + 103941.

It is an arithmetic number, because the mean of its divisors is an integer number (23034600).

Almost surely, 2^320640066 is an apocalyptic number.

320640066 is an abundant number, since it is smaller than the sum of its proper divisors (416467134).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

320640066 is a wasteful number, since it uses less digits than its factorization.

320640066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204791 (or 204785 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

The square root of 320640066 is about 17906.4252713935. The cubic root of 320640066 is about 684.4461155598.

Adding to 320640066 its reverse (660046023), we get a palindrome (980686089).

The spelling of 320640066 in words is "three hundred twenty million, six hundred forty thousand, sixty-six".