19809659699 has 4 divisors (see below), whose sum is σ = 19984966536. Its totient is φ = 19634352864.

The previous prime is 19809659689. The next prime is 19809659729. The reversal of 19809659699 is 99695690891.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19809659699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19809659609) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87653249 + ... + 87653474.

It is an arithmetic number, because the mean of its divisors is an integer number (4996241634).

Almost surely, 2^19809659699 is an apocalyptic number.

19809659699 is a deficient number, since it is larger than the sum of its proper divisors (175306837).

19809659699 is a wasteful number, since it uses less digits than its factorization.

19809659699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175306836.

The product of its (nonzero) digits is 85030560, while the sum is 71.

The spelling of 19809659699 in words is "nineteen billion, eight hundred nine million, six hundred fifty-nine thousand, six hundred ninety-nine".