28505825 has 6 divisors (see below), whose sum is σ = 35347254. Its totient is φ = 22804640.

The previous prime is 28505803. The next prime is 28505857. The reversal of 28505825 is 52850582.

It can be written as a sum of positive squares in 3 ways, for example, as 107584 + 28398241 = 328^2 + 5329^2 .

It is not a de Polignac number, because 28505825 - 2¹⁴ = 28489441 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 570092 + ... + 570141.

It is an arithmetic number, because the mean of its divisors is an integer number (5891209).

Almost surely, 2^28505825 is an apocalyptic number.

28505825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28505825 is a deficient number, since it is larger than the sum of its proper divisors (6841429).

28505825 is a wasteful number, since it uses less digits than its factorization.

28505825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1140243 (or 1140238 counting only the distinct ones).

The product of its (nonzero) digits is 32000, while the sum is 35.

The square root of 28505825 is about 5339.0846593775. The cubic root of 28505825 is about 305.4765460854.

The spelling of 28505825 in words is "twenty-eight million, five hundred five thousand, eight hundred twenty-five".