664728078 has 32 divisors (see below), whose sum is σ = 1524201984. Its totient is φ = 189319392.

The previous prime is 664728073. The next prime is 664728089. The reversal of 664728078 is 870827466.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664728073) 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 15 ways as a sum of consecutive naturals, for example, 11650 + ... + 38277.

It is an arithmetic number, because the mean of its divisors is an integer number (47631312).

Almost surely, 2^664728078 is an apocalyptic number.

664728078 is an abundant number, since it is smaller than the sum of its proper divisors (859473906).

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

664728078 is a wasteful number, since it uses less digits than its factorization.

664728078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50256.

The product of its (nonzero) digits is 903168, while the sum is 48.

The square root of 664728078 is about 25782.3210359347. The cubic root of 664728078 is about 872.7328860573.

The spelling of 664728078 in words is "six hundred sixty-four million, seven hundred twenty-eight thousand, seventy-eight".