28102005 has 64 divisors (see below), whose sum is σ = 52715520. Its totient is φ = 14188608.

The previous prime is 28102001. The next prime is 28102043. The reversal of 28102005 is 50020182.

It is not a de Polignac number, because 28102005 - 2² = 28102001 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28102001) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 272784 + ... + 272886.

It is an arithmetic number, because the mean of its divisors is an integer number (823680).

Almost surely, 2^28102005 is an apocalyptic number.

It is an amenable number.

28102005 is a deficient number, since it is larger than the sum of its proper divisors (24613515).

28102005 is a wasteful number, since it uses less digits than its factorization.

28102005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 28102005 is about 5301.1324261897. The cubic root of 28102005 is about 304.0271970416.

Adding to 28102005 its reverse (50020182), we get a palindrome (78122187).

The spelling of 28102005 in words is "twenty-eight million, one hundred two thousand, five".