28085817 has 4 divisors (see below), whose sum is σ = 37447760. Its totient is φ = 18723876.

The previous prime is 28085809. The next prime is 28085831. The reversal of 28085817 is 71858082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28085817 - 2³ = 28085809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28085807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4680967 + ... + 4680972.

It is an arithmetic number, because the mean of its divisors is an integer number (9361940).

Almost surely, 2^28085817 is an apocalyptic number.

It is an amenable number.

28085817 is a deficient number, since it is larger than the sum of its proper divisors (9361943).

28085817 is an equidigital number, since it uses as much as digits as its factorization.

28085817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9361942.

The product of its (nonzero) digits is 35840, while the sum is 39.

The square root of 28085817 is about 5299.6053626662. The cubic root of 28085817 is about 303.9688081166.

It can be divided in two parts, 280858 and 17, that added together give a triangular number (280875 = T₇₄₉).

The spelling of 28085817 in words is "twenty-eight million, eighty-five thousand, eight hundred seventeen".