28081805 has 16 divisors (see below), whose sum is σ = 34401024. Its totient is φ = 22002240.

The previous prime is 28081793. The next prime is 28081811. The reversal of 28081805 is 50818082.

It is not a de Polignac number, because 28081805 - 2¹⁴ = 28065421 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 15 ways as a sum of consecutive naturals, for example, 64940 + ... + 65370.

It is an arithmetic number, because the mean of its divisors is an integer number (2150064).

Almost surely, 2^28081805 is an apocalyptic number.

It is an amenable number.

28081805 is a deficient number, since it is larger than the sum of its proper divisors (6319219).

28081805 is a wasteful number, since it uses less digits than its factorization.

28081805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 676.

The product of its (nonzero) digits is 5120, while the sum is 32.

The square root of 28081805 is about 5299.2268303971. The cubic root of 28081805 is about 303.9543336587.

Adding to 28081805 its reverse (50818082), we get a palindrome (78899887).

The spelling of 28081805 in words is "twenty-eight million, eighty-one thousand, eight hundred five".