28108205 has 6 divisors (see below), whose sum is σ = 33744078. Its totient is φ = 22477080.

The previous prime is 28108193. The next prime is 28108211. The reversal of 28108205 is 50280182.

It can be written as a sum of positive squares in only one way, i.e., 22486564 + 5621641 = 4742^2 + 2371^2 .

It is not a de Polignac number, because 28108205 - 2¹⁶ = 28042669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10670 + ... + 13040.

It is an arithmetic number, because the mean of its divisors is an integer number (5624013).

Almost surely, 2^28108205 is an apocalyptic number.

It is an amenable number.

28108205 is a deficient number, since it is larger than the sum of its proper divisors (5635873).

28108205 is an frugal number, since it uses more digits than its factorization.

28108205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4747 (or 2376 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 28108205 is about 5301.7171746520. The cubic root of 28108205 is about 304.0495540468.

Multiplying 28108205 by its product of nonzero digits (1280), we get a square (35978502400 = 189680²).

Adding to 28108205 its reverse (50280182), we get a palindrome (78388387).

The spelling of 28108205 in words is "twenty-eight million, one hundred eight thousand, two hundred five".