28105861 has 12 divisors (see below), whose sum is σ = 32885580. Its totient is φ = 23950080.

The previous prime is 28105853. The next prime is 28105867. The reversal of 28105861 is 16850182.

It can be written as a sum of positive squares in 2 ways, for example, as 9572836 + 18533025 = 3094^2 + 4305^2 .

It is not a de Polignac number, because 28105861 - 2³ = 28105853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28105867) 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 11 ways as a sum of consecutive naturals, for example, 7285 + ... + 10453.

It is an arithmetic number, because the mean of its divisors is an integer number (2740465).

Almost surely, 2^28105861 is an apocalyptic number.

It is an amenable number.

28105861 is a deficient number, since it is larger than the sum of its proper divisors (4779719).

28105861 is a wasteful number, since it uses less digits than its factorization.

28105861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3364 (or 3357 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 31.

The square root of 28105861 is about 5301.4961095902. The cubic root of 28105861 is about 304.0411020430.

The spelling of 28105861 in words is "twenty-eight million, one hundred five thousand, eight hundred sixty-one".