664609375 has 32 divisors (see below), whose sum is σ = 853122816. Its totient is φ = 517500000.

The previous prime is 664609367. The next prime is 664609397. The reversal of 664609375 is 573906466.

It is not a de Polignac number, because 664609375 - 2³ = 664609367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 3671785 + ... + 3671965.

It is an arithmetic number, because the mean of its divisors is an integer number (26660088).

Almost surely, 2^664609375 is an apocalyptic number.

664609375 is a deficient number, since it is larger than the sum of its proper divisors (188513441).

664609375 is an frugal number, since it uses more digits than its factorization.

With its predecessor (664609374) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (233).

664609375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 46.

The square root of 664609375 is about 25780.0189100008. The cubic root of 664609375 is about 872.6809338970.

The spelling of 664609375 in words is "six hundred sixty-four million, six hundred nine thousand, three hundred seventy-five".