8646781372681 has 9 divisors (see below), whose sum is σ = 9185388332821. Its totient is φ = 8138100125632.

The previous prime is 8646781372661. The next prime is 8646781372693. The reversal of 8646781372681 is 1862731876468.

The square root of 8646781372681 is 2940541.

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

It can be written as a sum of positive squares in 4 ways, for example, as 670336825081 + 7976444547600 = 818741^2 + 2824260^2 .

It is not a de Polignac number, because 8646781372681 - 2⁷ = 8646781372553 is a prime.

It is a super-2 number, since 2×8646781372681² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8646781372631) 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, 49902711 + ... + 50075683.

Almost surely, 2^{8646781372681} is an apocalyptic number.

8646781372681 is the 2940541-st square number.

8646781372681 is the 1470271-st centered octagonal number.

It is an amenable number.

8646781372681 is a deficient number, since it is larger than the sum of its proper divisors (538606960140).

8646781372681 is an frugal number, since it uses more digits than its factorization.

8646781372681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345980 (or 172990 counting only the distinct ones).

The product of its digits is 130056192, while the sum is 67.

The spelling of 8646781372681 in words is "eight trillion, six hundred forty-six billion, seven hundred eighty-one million, three hundred seventy-two thousand, six hundred eighty-one".