28055605 has 4 divisors (see below), whose sum is σ = 33666732. Its totient is φ = 22444480.

The previous prime is 28055581. The next prime is 28055623. The reversal of 28055605 is 50655082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16826404 + 11229201 = 4102^2 + 3351^2 .

It is not a de Polignac number, because 28055605 - 2¹³ = 28047413 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, 2805556 + ... + 2805565.

It is an arithmetic number, because the mean of its divisors is an integer number (8416683).

Almost surely, 2^28055605 is an apocalyptic number.

It is an amenable number.

28055605 is a deficient number, since it is larger than the sum of its proper divisors (5611127).

28055605 is an equidigital number, since it uses as much as digits as its factorization.

28055605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5611126.

The product of its (nonzero) digits is 12000, while the sum is 31.

The square root of 28055605 is about 5296.7541947876. The cubic root of 28055605 is about 303.8597756168.

The spelling of 28055605 in words is "twenty-eight million, fifty-five thousand, six hundred five".