8191643 has 2 divisors, whose sum is σ = 8191644. Its totient is φ = 8191642.

The previous prime is 8191639. The next prime is 8191691. The reversal of 8191643 is 3461918.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8191643 - 2² = 8191639 is a prime.

It is not a weakly prime, because it can be changed into another prime (8191613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4095821 + 4095822.

It is an arithmetic number, because the mean of its divisors is an integer number (4095822).

Almost surely, 2^8191643 is an apocalyptic number.

8191643 is a deficient number, since it is larger than the sum of its proper divisors (1).

8191643 is an equidigital number, since it uses as much as digits as its factorization.

8191643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 32.

The square root of 8191643 is about 2862.1046451868. The cubic root of 8191643 is about 201.5844396085.

The spelling of 8191643 in words is "eight million, one hundred ninety-one thousand, six hundred forty-three".