19819799999 has 2 divisors, whose sum is σ = 19819800000. Its totient is φ = 19819799998.

The previous prime is 19819799977. The next prime is 19819800061. The reversal of 19819799999 is 99999791891.

It is a weak prime.

It is an emirp because it is prime and its reverse (99999791891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19819799999 - 2⁸ = 19819799743 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19819799929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9909899999 + 9909900000.

It is an arithmetic number, because the mean of its divisors is an integer number (9909900000).

Almost surely, 2^19819799999 is an apocalyptic number.

19819799999 is a deficient number, since it is larger than the sum of its proper divisors (1).

19819799999 is an equidigital number, since it uses as much as digits as its factorization.

19819799999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 267846264, while the sum is 80.

The spelling of 19819799999 in words is "nineteen billion, eight hundred nineteen million, seven hundred ninety-nine thousand, nine hundred ninety-nine".