19399691 has 2 divisors, whose sum is σ = 19399692. Its totient is φ = 19399690.

The previous prime is 19399687. The next prime is 19399697. The reversal of 19399691 is 19699391.

It is a weak prime.

It is an emirp because it is prime and its reverse (19699391) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19399691 - 2² = 19399687 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19399697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9699845 + 9699846.

It is an arithmetic number, because the mean of its divisors is an integer number (9699846).

Almost surely, 2^19399691 is an apocalyptic number.

19399691 is a deficient number, since it is larger than the sum of its proper divisors (1).

19399691 is an equidigital number, since it uses as much as digits as its factorization.

19399691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 118098, while the sum is 47.

The square root of 19399691 is about 4404.5080315513. The cubic root of 19399691 is about 268.6983116026.

The spelling of 19399691 in words is "nineteen million, three hundred ninety-nine thousand, six hundred ninety-one".