28320055 has 4 divisors (see below), whose sum is σ = 33984072. Its totient is φ = 22656040.

The previous prime is 28320041. The next prime is 28320091. The reversal of 28320055 is 55002382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55002382 = 2 ⋅27501191.

It is not a de Polignac number, because 28320055 - 2¹³ = 28311863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 2832001 + ... + 2832010.

It is an arithmetic number, because the mean of its divisors is an integer number (8496018).

Almost surely, 2^28320055 is an apocalyptic number.

28320055 is a deficient number, since it is larger than the sum of its proper divisors (5664017).

28320055 is an equidigital number, since it uses as much as digits as its factorization.

28320055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5664016.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 28320055 is about 5321.6590458240. The cubic root of 28320055 is about 304.8115112374.

The spelling of 28320055 in words is "twenty-eight million, three hundred twenty thousand, fifty-five".