28365860573521 has 3 divisors (see below), whose sum is σ = 28365865899483. Its totient is φ = 28365855247560.

The previous prime is 28365860573389. The next prime is 28365860573527. The reversal of 28365860573521 is 12537506856382.

The square root of 28365860573521 is 5325961.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1686982747921 + 26678877825600 = 1298839^2 + 5165160^2 .

It is not a de Polignac number, because 28365860573521 - 2²⁷ = 28365726355793 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28365860573521.

It is not an unprimeable number, because it can be changed into a prime (28365860573527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2662981 + ... + 7988941.

It is an arithmetic number, because the mean of its divisors is an integer number (9455288633161).

Almost surely, 2^{28365860573521} is an apocalyptic number.

28365860573521 is the 5325961-st square number.

28365860573521 is the 2662981-st centered octagonal number.

It is an amenable number.

28365860573521 is a deficient number, since it is larger than the sum of its proper divisors (5325962).

28365860573521 is an frugal number, since it uses more digits than its factorization.

28365860573521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10651922 (or 5325961 counting only the distinct ones).

The product of its (nonzero) digits is 72576000, while the sum is 61.

The spelling of 28365860573521 in words is "twenty-eight trillion, three hundred sixty-five billion, eight hundred sixty million, five hundred seventy-three thousand, five hundred twenty-one".