8672816681 has 2 divisors, whose sum is σ = 8672816682. Its totient is φ = 8672816680.

The previous prime is 8672816591. The next prime is 8672816683. The reversal of 8672816681 is 1866182768.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8649930025 + 22886656 = 93005^2 + 4784^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8672816681 is a prime.

It is a super-2 number, since 2×8672816681² (a number of 21 digits) contains 22 as substring.

Together with 8672816683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (8672816683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4336408340 + 4336408341.

It is an arithmetic number, because the mean of its divisors is an integer number (4336408341).

Almost surely, 2^8672816681 is an apocalyptic number.

It is an amenable number.

8672816681 is a deficient number, since it is larger than the sum of its proper divisors (1).

8672816681 is an equidigital number, since it uses as much as digits as its factorization.

8672816681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1548288, while the sum is 53.

The square root of 8672816681 is about 93127.9586429339. The cubic root of 8672816681 is about 2054.5658044348.

The spelling of 8672816681 in words is "eight billion, six hundred seventy-two million, eight hundred sixteen thousand, six hundred eighty-one".