813082727521 has 9 divisors (see below), whose sum is σ = 817535162899. Its totient is φ = 808654424800.

The previous prime is 813082727519. The next prime is 813082727531. The reversal of 813082727521 is 125727280318.

The square root of 813082727521 is 901711.

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

813082727521 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 only one way, i.e., 439517287521 + 373565440000 = 662961^2 + 611200^2 .

It is not a de Polignac number, because 813082727521 - 2¹ = 813082727519 is a prime.

It is a super-2 number, since 2×813082727521² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (813082727531) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 172224441 + ... + 172229161.

Almost surely, 2^813082727521 is an apocalyptic number.

813082727521 is the 901711-st square number.

813082727521 is the 450856-th centered octagonal number.

It is an amenable number.

813082727521 is a deficient number, since it is larger than the sum of its proper divisors (4452435378).

813082727521 is an frugal number, since it uses more digits than its factorization.

813082727521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9824 (or 4912 counting only the distinct ones).

The product of its (nonzero) digits is 376320, while the sum is 46.

The spelling of 813082727521 in words is "eight hundred thirteen billion, eighty-two million, seven hundred twenty-seven thousand, five hundred twenty-one".