8644644681 has 16 divisors (see below), whose sum is σ = 12141080640. Its totient is φ = 5456064960.

The previous prime is 8644644677. The next prime is 8644644769. The reversal of 8644644681 is 1864464468.

It is a happy number.

It is not a de Polignac number, because 8644644681 - 2² = 8644644677 is a prime.

It is a super-2 number, since 2×8644644681² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (8644644881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34311 + ... + 135891.

It is an arithmetic number, because the mean of its divisors is an integer number (758817540).

Almost surely, 2^8644644681 is an apocalyptic number.

It is an amenable number.

8644644681 is a deficient number, since it is larger than the sum of its proper divisors (3496435959).

8644644681 is a wasteful number, since it uses less digits than its factorization.

8644644681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103096.

The product of its digits is 3538944, while the sum is 51.

The square root of 8644644681 is about 92976.5813578882. The cubic root of 8644644681 is about 2052.3387688830.

The spelling of 8644644681 in words is "eight billion, six hundred forty-four million, six hundred forty-four thousand, six hundred eighty-one".