9813865678681 has 27 divisors (see below), whose sum is σ = 10515090530847. Its totient is φ = 9157534948800.

The previous prime is 9813865678679. The next prime is 9813865678763. The reversal of 9813865678681 is 1868765683189.

The square root of 9813865678681 is 3132709.

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

It can be written as a sum of positive squares in only one way, i.e., 7640552864025 + 2173312814656 = 2764155^2 + 1474216^2 .

It is not a de Polignac number, because 9813865678681 - 2¹ = 9813865678679 is a prime.

It is a super-2 number, since 2×9813865678681² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 9813865678598 and 9813865678607.

It is not an unprimeable number, because it can be changed into a prime (9813865678601) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 6763518006 + ... + 6763519456.

Almost surely, 2^{9813865678681} is an apocalyptic number.

9813865678681 is the 3132709-th square number.

9813865678681 is the 1566355-th centered octagonal number.

It is an amenable number.

9813865678681 is a deficient number, since it is larger than the sum of its proper divisors (701224852166).

9813865678681 is an frugal number, since it uses more digits than its factorization.

9813865678681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3190 (or 1595 counting only the distinct ones).

The product of its digits is 836075520, while the sum is 76.

The spelling of 9813865678681 in words is "nine trillion, eight hundred thirteen billion, eight hundred sixty-five million, six hundred seventy-eight thousand, six hundred eighty-one".