398664640 has 112 divisors (see below), whose sum is σ = 1063959264. Its totient is φ = 141004800.

The previous prime is 398664611. The next prime is 398664659. The reversal of 398664640 is 46466893.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 128710 + ... + 131770.

Almost surely, 2^398664640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 398664640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (531979632).

398664640 is an abundant number, since it is smaller than the sum of its proper divisors (665294624).

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

398664640 is a wasteful number, since it uses less digits than its factorization.

398664640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3126 (or 3116 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 46.

The square root of 398664640 is about 19966.5880911086. The cubic root of 398664640 is about 735.9854675770.

The spelling of 398664640 in words is "three hundred ninety-eight million, six hundred sixty-four thousand, six hundred forty".