8643906881 has 2 divisors, whose sum is σ = 8643906882. Its totient is φ = 8643906880.

The previous prime is 8643906871. The next prime is 8643906883. The reversal of 8643906881 is 1886093468.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6133395856 + 2510511025 = 78316^2 + 50105^2 .

It is a cyclic number.

It is not a de Polignac number, because 8643906881 - 2¹⁰ = 8643905857 is a prime.

It is a super-2 number, since 2×8643906881² (a number of 21 digits) contains 22 as substring.

Together with 8643906883, 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 (8643906883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4321953440 + 4321953441.

It is an arithmetic number, because the mean of its divisors is an integer number (4321953441).

Almost surely, 2^8643906881 is an apocalyptic number.

It is an amenable number.

8643906881 is a deficient number, since it is larger than the sum of its proper divisors (1).

8643906881 is an equidigital number, since it uses as much as digits as its factorization.

8643906881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1990656, while the sum is 53.

The square root of 8643906881 is about 92972.6136074489. The cubic root of 8643906881 is about 2052.2803798001.

The spelling of 8643906881 in words is "eight billion, six hundred forty-three million, nine hundred six thousand, eight hundred eighty-one".