8398566643 has 2 divisors, whose sum is σ = 8398566644. Its totient is φ = 8398566642.

The previous prime is 8398566581. The next prime is 8398566809. The reversal of 8398566643 is 3466658938.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8398566643 is a prime.

It is not a weakly prime, because it can be changed into another prime (8398566443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4199283321 + 4199283322.

It is an arithmetic number, because the mean of its divisors is an integer number (4199283322).

Almost surely, 2^8398566643 is an apocalyptic number.

8398566643 is a deficient number, since it is larger than the sum of its proper divisors (1).

8398566643 is an equidigital number, since it uses as much as digits as its factorization.

8398566643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22394880, while the sum is 58.

The square root of 8398566643 is about 91643.6939619961. The cubic root of 8398566643 is about 2032.6770833356.

The spelling of 8398566643 in words is "eight billion, three hundred ninety-eight million, five hundred sixty-six thousand, six hundred forty-three".