8681965921 has 4 divisors (see below), whose sum is σ = 8726037012. Its totient is φ = 8637894832.

The previous prime is 8681965907. The next prime is 8681965939. The reversal of 8681965921 is 1295691868.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8397706321 + 284259600 = 91639^2 + 16860^2 .

It is a cyclic number.

It is not a de Polignac number, because 8681965921 - 2⁵ = 8681965889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8681965321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22035250 + ... + 22035643.

It is an arithmetic number, because the mean of its divisors is an integer number (2181509253).

Almost surely, 2^8681965921 is an apocalyptic number.

It is an amenable number.

8681965921 is a deficient number, since it is larger than the sum of its proper divisors (44071091).

8681965921 is a wasteful number, since it uses less digits than its factorization.

8681965921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44071090.

The product of its digits is 1866240, while the sum is 55.

The square root of 8681965921 is about 93177.0675702986. The cubic root of 8681965921 is about 2055.2880269105.

The spelling of 8681965921 in words is "eight billion, six hundred eighty-one million, nine hundred sixty-five thousand, nine hundred twenty-one".