664668768 has 96 divisors (see below), whose sum is σ = 1812851712. Its totient is φ = 213004800.

The previous prime is 664668751. The next prime is 664668769. The reversal of 664668768 is 867866466.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664668769) 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 15 ways as a sum of consecutive naturals, for example, 514203 + ... + 515493.

It is an arithmetic number, because the mean of its divisors is an integer number (18883872).

Almost surely, 2^664668768 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664668768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (906425856).

664668768 is an abundant number, since it is smaller than the sum of its proper divisors (1148182944).

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

664668768 is a wasteful number, since it uses less digits than its factorization.

664668768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1508 (or 1500 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 57.

The square root of 664668768 is about 25781.1708035147. The cubic root of 664668768 is about 872.7069289134.

The spelling of 664668768 in words is "six hundred sixty-four million, six hundred sixty-eight thousand, seven hundred sixty-eight".