398755728 has 180 divisors, whose sum is σ = 1340771328. Its totient is φ = 110194560.

The previous prime is 398755703. The next prime is 398755733. The reversal of 398755728 is 827557893.

398755728 is a `hidden beast` number, since 3 + 9 + 87 + 557 + 2 + 8 = 666.

It is a super-2 number, since 2×398755728² = 318012261225619968, which contains 22 as substring.

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 35 ways as a sum of consecutive naturals, for example, 217825 + ... + 219647.

Almost surely, 2^398755728 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 398755728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (670385664).

398755728 is an abundant number, since it is smaller than the sum of its proper divisors (942015600).

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

398755728 is a wasteful number, since it uses less digits than its factorization.

398755728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1882 (or 1866 counting only the distinct ones).

The product of its digits is 4233600, while the sum is 54.

The square root of 398755728 is about 19968.8689714766. The cubic root of 398755728 is about 736.0415166404.

The spelling of 398755728 in words is "three hundred ninety-eight million, seven hundred fifty-five thousand, seven hundred twenty-eight".