399138528 has 24 divisors (see below), whose sum is σ = 1047738888. Its totient is φ = 133046144.

The previous prime is 399138511. The next prime is 399138577. The reversal of 399138528 is 825831993.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2078751 + ... + 2078942.

It is an arithmetic number, because the mean of its divisors is an integer number (43655787).

Almost surely, 2^399138528 is an apocalyptic number.

It is an amenable number.

399138528 is an abundant number, since it is smaller than the sum of its proper divisors (648600360).

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

399138528 is a wasteful number, since it uses less digits than its factorization.

399138528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4157706 (or 4157698 counting only the distinct ones).

The product of its digits is 466560, while the sum is 48.

The square root of 399138528 is about 19978.4515916524. The cubic root of 399138528 is about 736.2769712141.

The spelling of 399138528 in words is "three hundred ninety-nine million, one hundred thirty-eight thousand, five hundred twenty-eight".