28512725 has 12 divisors (see below), whose sum is σ = 35672196. Its totient is φ = 22606080.

The previous prime is 28512719. The next prime is 28512739. The reversal of 28512725 is 52721582.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 5692996 + 22819729 = 2386^2 + 4777^2 .

It is not a de Polignac number, because 28512725 - 2¹⁰ = 28511701 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28512691 and 28512700.

It is a congruent number.

It is an unprimeable number.

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, 2222 + ... + 7871.

It is an arithmetic number, because the mean of its divisors is an integer number (2972683).

Almost surely, 2^28512725 is an apocalyptic number.

28512725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28512725 is a deficient number, since it is larger than the sum of its proper divisors (7159471).

28512725 is a wasteful number, since it uses less digits than its factorization.

28512725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10216 (or 10211 counting only the distinct ones).

The product of its digits is 11200, while the sum is 32.

The square root of 28512725 is about 5339.7307984579. The cubic root of 28512725 is about 305.5011915526.

The spelling of 28512725 in words is "twenty-eight million, five hundred twelve thousand, seven hundred twenty-five".