28515625 has 18 divisors (see below), whose sum is σ = 36132794. Its totient is φ = 22500000.

The previous prime is 28515611. The next prime is 28515631. The reversal of 28515625 is 52651582.

28515625 is nontrivially palindromic in base 8.

It can be written as a sum of positive squares in 9 ways, for example, as 10291264 + 18224361 = 3208^2 + 4269^2 .

It is not a de Polignac number, because 28515625 - 2¹¹ = 28513577 is a prime.

It is a Duffinian 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 17 ways as a sum of consecutive naturals, for example, 390589 + ... + 390661.

Almost surely, 2^28515625 is an apocalyptic number.

28515625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28515625 is a deficient number, since it is larger than the sum of its proper divisors (7617169).

28515625 is an frugal number, since it uses more digits than its factorization.

28515625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113 (or 78 counting only the distinct ones).

The product of its digits is 24000, while the sum is 34.

The square root of 28515625 is about 5340.0023408235. The cubic root of 28515625 is about 305.5115486057.

It can be divided in two parts, 285156 and 25, that multiplied together give a square (7128900 = 2670²).

The spelling of 28515625 in words is "twenty-eight million, five hundred fifteen thousand, six hundred twenty-five".