28518225 has 24 divisors (see below), whose sum is σ = 47303520. Its totient is φ = 15160320.

The previous prime is 28518211. The next prime is 28518227. The reversal of 28518225 is 52281582.

It is not a de Polignac number, because 28518225 - 2⁴ = 28518209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28518227) 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 23 ways as a sum of consecutive naturals, for example, 42946 + ... + 43604.

It is an arithmetic number, because the mean of its divisors is an integer number (1970980).

Almost surely, 2^28518225 is an apocalyptic number.

28518225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

28518225 is a deficient number, since it is larger than the sum of its proper divisors (18785295).

28518225 is a wasteful number, since it uses less digits than its factorization.

28518225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1249 (or 1244 counting only the distinct ones).

The product of its digits is 12800, while the sum is 33.

The square root of 28518225 is about 5340.2457808607. The cubic root of 28518225 is about 305.5208336425.

The spelling of 28518225 in words is "twenty-eight million, five hundred eighteen thousand, two hundred twenty-five".