28404211 has 4 divisors (see below), whose sum is σ = 30986424. Its totient is φ = 25822000.

The previous prime is 28404203. The next prime is 28404239. The reversal of 28404211 is 11240482.

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

It is a cyclic number.

It is not a de Polignac number, because 28404211 - 2³ = 28404203 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28404251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1291090 + ... + 1291111.

It is an arithmetic number, because the mean of its divisors is an integer number (7746606).

Almost surely, 2^28404211 is an apocalyptic number.

28404211 is a deficient number, since it is larger than the sum of its proper divisors (2582213).

28404211 is a wasteful number, since it uses less digits than its factorization.

28404211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2582212.

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 28404211 is about 5329.5601131801. The cubic root of 28404211 is about 305.1131390706.

Adding to 28404211 its reverse (11240482), we get a palindrome (39644693).

The spelling of 28404211 in words is "twenty-eight million, four hundred four thousand, two hundred eleven".