28547819521 has 27 divisors (see below), whose sum is σ = 31785354363. Its totient is φ = 25628004480.

The previous prime is 28547819491. The next prime is 28547819569. The reversal of 28547819521 is 12591874582.

The square root of 28547819521 is 168961.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 16253445121 + 12294374400 = 127489^2 + 110880^2 .

It is not a de Polignac number, because 28547819521 - 2¹³ = 28547811329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28547819021) 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 26 ways as a sum of consecutive naturals, for example, 90056055 + ... + 90056371.

Almost surely, 2^28547819521 is an apocalyptic number.

28547819521 is the 168961-st square number.

28547819521 is the 84481-st centered octagonal number.

It is an amenable number.

28547819521 is a deficient number, since it is larger than the sum of its proper divisors (3237534842).

28547819521 is an frugal number, since it uses more digits than its factorization.

28547819521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742 (or 371 counting only the distinct ones).

The product of its digits is 1612800, while the sum is 52.

The spelling of 28547819521 in words is "twenty-eight billion, five hundred forty-seven million, eight hundred nineteen thousand, five hundred twenty-one".