28306404 has 36 divisors (see below), whose sum is σ = 81774784. Its totient is φ = 8087472.

The previous prime is 28306393. The next prime is 28306459. The reversal of 28306404 is 40460382.

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

It is a super-2 number, since 2×28306404² = 1602505014822432, which contains 22 as substring.

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, 55912 + ... + 56415.

Almost surely, 2^28306404 is an apocalyptic number.

It is an amenable number.

28306404 is an abundant number, since it is smaller than the sum of its proper divisors (53468380).

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

28306404 is a wasteful number, since it uses less digits than its factorization.

28306404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112344 (or 112339 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 28306404 is about 5320.3763024809. The cubic root of 28306404 is about 304.7625276850.

Adding to 28306404 its reverse (40460382), we get a palindrome (68766786).

The spelling of 28306404 in words is "twenty-eight million, three hundred six thousand, four hundred four".