28521765 has 48 divisors (see below), whose sum is σ = 51217920. Its totient is φ = 14676480.

The previous prime is 28521751. The next prime is 28521797. The reversal of 28521765 is 56712582.

It is a happy number.

It is not a de Polignac number, because 28521765 - 2⁷ = 28521637 is a prime.

It is a Curzon number.

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 47 ways as a sum of consecutive naturals, for example, 252349 + ... + 252461.

It is an arithmetic number, because the mean of its divisors is an integer number (1067040).

Almost surely, 2^28521765 is an apocalyptic number.

It is an amenable number.

28521765 is a deficient number, since it is larger than the sum of its proper divisors (22696155).

28521765 is a wasteful number, since it uses less digits than its factorization.

28521765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274 (or 271 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 28521765 is about 5340.5772159945. The cubic root of 28521765 is about 305.5334746701.

The spelling of 28521765 in words is "twenty-eight million, five hundred twenty-one thousand, seven hundred sixty-five".