19519163491 has 2 divisors, whose sum is σ = 19519163492. Its totient is φ = 19519163490.

The previous prime is 19519163449. The next prime is 19519163537. The reversal of 19519163491 is 19436191591.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19519163491 - 2¹¹ = 19519161443 is a prime.

It is not a weakly prime, because it can be changed into another prime (19519163401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9759581745 + 9759581746.

It is an arithmetic number, because the mean of its divisors is an integer number (9759581746).

Almost surely, 2^19519163491 is an apocalyptic number.

19519163491 is a deficient number, since it is larger than the sum of its proper divisors (1).

19519163491 is an equidigital number, since it uses as much as digits as its factorization.

19519163491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 262440, while the sum is 49.

The spelling of 19519163491 in words is "nineteen billion, five hundred nineteen million, one hundred sixty-three thousand, four hundred ninety-one".