199988490997 has 4 divisors (see below), whose sum is σ = 200162244096. Its totient is φ = 199814737900.

The previous prime is 199988490967. The next prime is 199988491099. The reversal of 199988490997 is 799094889991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199988490997 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 199988490997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199988490967) 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, 86874823 + ... + 86877124.

It is an arithmetic number, because the mean of its divisors is an integer number (50040561024).

Almost surely, 2^199988490997 is an apocalyptic number.

It is an amenable number.

199988490997 is a deficient number, since it is larger than the sum of its proper divisors (173753099).

199988490997 is a wasteful number, since it uses less digits than its factorization.

199988490997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173753098.

The product of its (nonzero) digits is 952342272, while the sum is 82.

The spelling of 199988490997 in words is "one hundred ninety-nine billion, nine hundred eighty-eight million, four hundred ninety thousand, nine hundred ninety-seven".