28409205 has 32 divisors (see below), whose sum is σ = 49932288. Its totient is φ = 13678400.

The previous prime is 28409203. The next prime is 28409207. The reversal of 28409205 is 50290482.

It is an interprime number because it is at equal distance from previous prime (28409203) and next prime (28409207).

It is not a de Polignac number, because 28409205 - 2¹ = 28409203 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28409203) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27040 + ... + 28070.

It is an arithmetic number, because the mean of its divisors is an integer number (1560384).

Almost surely, 2^28409205 is an apocalyptic number.

It is an amenable number.

28409205 is a deficient number, since it is larger than the sum of its proper divisors (21523083).

28409205 is a wasteful number, since it uses less digits than its factorization.

28409205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1217.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 28409205 is about 5330.0286115555. The cubic root of 28409205 is about 305.1310195852.

Adding to 28409205 its reverse (50290482), we get a palindrome (78699687).

The spelling of 28409205 in words is "twenty-eight million, four hundred nine thousand, two hundred five".