19516259249 has 2 divisors, whose sum is σ = 19516259250. Its totient is φ = 19516259248.

The previous prime is 19516259221. The next prime is 19516259251. The reversal of 19516259249 is 94295261591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18640987024 + 875272225 = 136532^2 + 29585^2 .

It is an emirp because it is prime and its reverse (94295261591) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19516259249 - 2²⁴ = 19499482033 is a prime.

Together with 19516259251, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19516259249.

It is not a weakly prime, because it can be changed into another prime (19516259209) 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, 9758129624 + 9758129625.

It is an arithmetic number, because the mean of its divisors is an integer number (9758129625).

Almost surely, 2^19516259249 is an apocalyptic number.

It is an amenable number.

19516259249 is a deficient number, since it is larger than the sum of its proper divisors (1).

19516259249 is an equidigital number, since it uses as much as digits as its factorization.

19516259249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1749600, while the sum is 53.

The spelling of 19516259249 in words is "nineteen billion, five hundred sixteen million, two hundred fifty-nine thousand, two hundred forty-nine".