28005265 has 8 divisors (see below), whose sum is σ = 33781608. Its totient is φ = 22287360.

The previous prime is 28005247. The next prime is 28005269. The reversal of 28005265 is 56250082.

It is a Cunningham number, because it is equal to 5292²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 6780816 + 21224449 = 2604^2 + 4607^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28005265 - 2¹⁷ = 27874193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28005269) 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 7 ways as a sum of consecutive naturals, for example, 13546 + ... + 15475.

It is an arithmetic number, because the mean of its divisors is an integer number (4222701).

Almost surely, 2^28005265 is an apocalyptic number.

It is an amenable number.

28005265 is a deficient number, since it is larger than the sum of its proper divisors (5776343).

28005265 is a wasteful number, since it uses less digits than its factorization.

28005265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29219.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 28005265 is about 5292.0000944822. Note that the first 4 decimals coincide. The cubic root of 28005265 is about 303.6779289006.

The spelling of 28005265 in words is "twenty-eight million, five thousand, two hundred sixty-five".