19968191 has 2 divisors, whose sum is σ = 19968192. Its totient is φ = 19968190.

The previous prime is 19968187. The next prime is 19968203. The reversal of 19968191 is 19186991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19968191 - 2² = 19968187 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19968181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9984095 + 9984096.

It is an arithmetic number, because the mean of its divisors is an integer number (9984096).

Almost surely, 2^19968191 is an apocalyptic number.

19968191 is a deficient number, since it is larger than the sum of its proper divisors (1).

19968191 is an equidigital number, since it uses as much as digits as its factorization.

19968191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 44.

The square root of 19968191 is about 4468.5781855082. The cubic root of 19968191 is about 271.2977804509.

The spelling of 19968191 in words is "nineteen million, nine hundred sixty-eight thousand, one hundred ninety-one".