19999800197 has 24 divisors (see below), whose sum is σ = 23170347360. Its totient is φ = 17202818880.

The previous prime is 19999800193. The next prime is 19999800199. The reversal of 19999800197 is 79100899991.

It is not a de Polignac number, because 19999800197 - 2² = 19999800193 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19999800193) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 144818 + ... + 246924.

It is an arithmetic number, because the mean of its divisors is an integer number (965431140).

Almost surely, 2^19999800197 is an apocalyptic number.

It is an amenable number.

19999800197 is a deficient number, since it is larger than the sum of its proper divisors (3170547163).

19999800197 is a wasteful number, since it uses less digits than its factorization.

19999800197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102213 (or 102200 counting only the distinct ones).

The product of its (nonzero) digits is 3306744, while the sum is 62.

The spelling of 19999800197 in words is "nineteen billion, nine hundred ninety-nine million, eight hundred thousand, one hundred ninety-seven".