11547866521 has 9 divisors (see below), whose sum is σ = 11840909149. Its totient is φ = 11261912800.

The previous prime is 11547866453. The next prime is 11547866563. The reversal of 11547866521 is 12566874511.

The square root of 11547866521 is 107461.

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

11547866521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 510262921 + 11037603600 = 22589^2 + 105060^2 .

It is not a de Polignac number, because 11547866521 - 2²⁹ = 11010995609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11547866021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4404591 + ... + 4407211.

Almost surely, 2^11547866521 is an apocalyptic number.

11547866521 is the 107461-st square number.

11547866521 is the 53731-st centered octagonal number.

It is an amenable number.

11547866521 is a deficient number, since it is larger than the sum of its proper divisors (293042628).

11547866521 is an frugal number, since it uses more digits than its factorization.

11547866521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5324 (or 2662 counting only the distinct ones).

The product of its digits is 403200, while the sum is 46.

The spelling of 11547866521 in words is "eleven billion, five hundred forty-seven million, eight hundred sixty-six thousand, five hundred twenty-one".