664398 has 24 divisors (see below), whose sum is σ = 1645488. Its totient is φ = 189792.

The previous prime is 664381. The next prime is 664403. The reversal of 664398 is 893466.

664398 is a `hidden beast` number, since 6 + 643 + 9 + 8 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2511 + ... + 2762.

It is an arithmetic number, because the mean of its divisors is an integer number (68562).

2⁶⁶⁴³⁹⁸ is an apocalyptic number.

664398 is an abundant number, since it is smaller than the sum of its proper divisors (981090).

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

664398 is a wasteful number, since it uses less digits than its factorization.

664398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5288 (or 5285 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 664398 is about 815.1061280594. The cubic root of 664398 is about 87.2588407119.

The spelling of 664398 in words is "six hundred sixty-four thousand, three hundred ninety-eight".