28028065 has 16 divisors (see below), whose sum is σ = 37472400. Its totient is φ = 19982592.

The previous prime is 28028057. The next prime is 28028069. The reversal of 28028065 is 56082082.

It can be written as a sum of positive squares in 8 ways, for example, as 4145296 + 23882769 = 2036^2 + 4887^2 .

It is a cyclic number.

It is not a de Polignac number, because 28028065 - 2³ = 28028057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28028069) 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 15 ways as a sum of consecutive naturals, for example, 5550 + ... + 9319.

It is an arithmetic number, because the mean of its divisors is an integer number (2342025).

Almost surely, 2^28028065 is an apocalyptic number.

It is an amenable number.

28028065 is a deficient number, since it is larger than the sum of its proper divisors (9444335).

28028065 is a wasteful number, since it uses less digits than its factorization.

28028065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14916.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 28028065 is about 5294.1538511834. The cubic root of 28028065 is about 303.7603179163.

The spelling of 28028065 in words is "twenty-eight million, twenty-eight thousand, sixty-five".