664041568 has 24 divisors (see below), whose sum is σ = 1335150432. Its totient is φ = 324955776.

The previous prime is 664041563. The next prime is 664041571. The reversal of 664041568 is 865140466.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 664041568.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664041563) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 219255 + ... + 222262.

It is an arithmetic number, because the mean of its divisors is an integer number (55631268).

Almost surely, 2^664041568 is an apocalyptic number.

It is an amenable number.

664041568 is an abundant number, since it is smaller than the sum of its proper divisors (671108864).

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

664041568 is a wasteful number, since it uses less digits than its factorization.

664041568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441574 (or 441566 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 664041568 is about 25769.0040164536. The cubic root of 664041568 is about 872.4323389868.

The spelling of 664041568 in words is "six hundred sixty-four million, forty-one thousand, five hundred sixty-eight".