28904473 has 4 divisors (see below), whose sum is σ = 31127908. Its totient is φ = 26681040.

The previous prime is 28904443. The next prime is 28904521. The reversal of 28904473 is 37440982.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3583449 + 25321024 = 1893^2 + 5032^2 .

It is a cyclic number.

It is not a de Polignac number, because 28904473 - 2²¹ = 26807321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28904413) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1111698 + ... + 1111723.

It is an arithmetic number, because the mean of its divisors is an integer number (7781977).

Almost surely, 2^28904473 is an apocalyptic number.

It is an amenable number.

28904473 is a deficient number, since it is larger than the sum of its proper divisors (2223435).

28904473 is a wasteful number, since it uses less digits than its factorization.

28904473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2223434.

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 28904473 is about 5376.2880317185. The cubic root of 28904473 is about 306.8939675629.

The spelling of 28904473 in words is "twenty-eight million, nine hundred four thousand, four hundred seventy-three".