28404073 has 4 divisors (see below), whose sum is σ = 28611540. Its totient is φ = 28196608.

The previous prime is 28404071. The next prime is 28404109. The reversal of 28404073 is 37040482.

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 22581504 + 5822569 = 4752^2 + 2413^2 .

It is a cyclic number.

It is not a de Polignac number, because 28404073 - 2¹ = 28404071 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28404071) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 103528 + ... + 103801.

It is an arithmetic number, because the mean of its divisors is an integer number (7152885).

Almost surely, 2^28404073 is an apocalyptic number.

It is an amenable number.

28404073 is a deficient number, since it is larger than the sum of its proper divisors (207467).

28404073 is a wasteful number, since it uses less digits than its factorization.

28404073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207466.

The product of its (nonzero) digits is 5376, while the sum is 28.

The square root of 28404073 is about 5329.5471665049. The cubic root of 28404073 is about 305.1126449458.

The spelling of 28404073 in words is "twenty-eight million, four hundred four thousand, seventy-three".