19491890291 has 2 divisors, whose sum is σ = 19491890292. Its totient is φ = 19491890290.

The previous prime is 19491890273. The next prime is 19491890317. The reversal of 19491890291 is 19209819491.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19491890291 - 2¹⁰ = 19491889267 is a prime.

It is not a weakly prime, because it can be changed into another prime (19491898291) 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, 9745945145 + 9745945146.

It is an arithmetic number, because the mean of its divisors is an integer number (9745945146).

Almost surely, 2^19491890291 is an apocalyptic number.

19491890291 is a deficient number, since it is larger than the sum of its proper divisors (1).

19491890291 is an equidigital number, since it uses as much as digits as its factorization.

19491890291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 53.

The spelling of 19491890291 in words is "nineteen billion, four hundred ninety-one million, eight hundred ninety thousand, two hundred ninety-one".