19699543823 has 4 divisors (see below), whose sum is σ = 19700270328. Its totient is φ = 19698817320.

The previous prime is 19699543813. The next prime is 19699543841. The reversal of 19699543823 is 32834599691.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19699543823 - 2²⁰ = 19698495247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19699543813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 320936 + ... + 377357.

It is an arithmetic number, because the mean of its divisors is an integer number (4925067582).

Almost surely, 2^19699543823 is an apocalyptic number.

19699543823 is a deficient number, since it is larger than the sum of its proper divisors (726505).

19699543823 is an equidigital number, since it uses as much as digits as its factorization.

19699543823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 726504.

The product of its digits is 12597120, while the sum is 59.

The spelling of 19699543823 in words is "nineteen billion, six hundred ninety-nine million, five hundred forty-three thousand, eight hundred twenty-three".