664528389 has 32 divisors (see below), whose sum is σ = 1031110656. Its totient is φ = 372859200.

The previous prime is 664528373. The next prime is 664528393. The reversal of 664528389 is 983825466.

It is not a de Polignac number, because 664528389 - 2⁴ = 664528373 is a prime.

It is a super-3 number, since 3×664528389³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664528309) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 268134 + ... + 270600.

It is an arithmetic number, because the mean of its divisors is an integer number (32222208).

Almost surely, 2^664528389 is an apocalyptic number.

It is an amenable number.

664528389 is a deficient number, since it is larger than the sum of its proper divisors (366582267).

664528389 is a wasteful number, since it uses less digits than its factorization.

664528389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2705.

The product of its digits is 2488320, while the sum is 51.

The square root of 664528389 is about 25778.4481495687. The cubic root of 664528389 is about 872.6454856013.

The spelling of 664528389 in words is "six hundred sixty-four million, five hundred twenty-eight thousand, three hundred eighty-nine".