28680205 has 8 divisors (see below), whose sum is σ = 34560504. Its totient is φ = 22848000.

The previous prime is 28680181. The next prime is 28680209. The reversal of 28680205 is 50208682.

It can be written as a sum of positive squares in 4 ways, for example, as 8726116 + 19954089 = 2954^2 + 4467^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28680205 - 2¹⁷ = 28549133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28680209) 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 7 ways as a sum of consecutive naturals, for example, 10696 + ... + 13105.

It is an arithmetic number, because the mean of its divisors is an integer number (4320063).

Almost surely, 2^28680205 is an apocalyptic number.

It is an amenable number.

28680205 is a deficient number, since it is larger than the sum of its proper divisors (5880299).

28680205 is a wasteful number, since it uses less digits than its factorization.

28680205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24047.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 28680205 is about 5355.3902752274. The cubic root of 28680205 is about 306.0981821443.

Adding to 28680205 its reverse (50208682), we get a palindrome (78888887).

The spelling of 28680205 in words is "twenty-eight million, six hundred eighty thousand, two hundred five".