664638424 has 8 divisors (see below), whose sum is σ = 1246197060. Its totient is φ = 332319208.

The previous prime is 664638397. The next prime is 664638433. The reversal of 664638424 is 424836466.

It is a tau number, because it is divible by the number of its divisors (8).

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 as a sum of consecutive naturals, namely, 41539894 + ... + 41539909.

Almost surely, 2^664638424 is an apocalyptic number.

It is an amenable number.

664638424 is a deficient number, since it is larger than the sum of its proper divisors (581558636).

664638424 is a wasteful number, since it uses less digits than its factorization.

664638424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83079809 (or 83079805 counting only the distinct ones).

The product of its digits is 663552, while the sum is 43.

The square root of 664638424 is about 25780.5823052933. The cubic root of 664638424 is about 872.6936482021.

The spelling of 664638424 in words is "six hundred sixty-four million, six hundred thirty-eight thousand, four hundred twenty-four".