400128804 has 36 divisors (see below), whose sum is σ = 1038776284. Its totient is φ = 129771072.

The previous prime is 400128793. The next prime is 400128857. The reversal of 400128804 is 408821004.

It can be written as a sum of positive squares in 2 ways, for example, as 141562404 + 258566400 = 11898^2 + 16080^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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 in 11 ways as a sum of consecutive naturals, for example, 148867 + ... + 151530.

Almost surely, 2^400128804 is an apocalyptic number.

It is an amenable number.

400128804 is an abundant number, since it is smaller than the sum of its proper divisors (638647480).

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

400128804 is a wasteful number, since it uses less digits than its factorization.

400128804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300444 (or 300439 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 400128804 is about 20003.2198408156. The cubic root of 400128804 is about 736.8853775729.

Adding to 400128804 its reverse (408821004), we get a palindrome (808949808).

The spelling of 400128804 in words is "four hundred million, one hundred twenty-eight thousand, eight hundred four".