199997849 has 4 divisors (see below), whose sum is σ = 200026320. Its totient is φ = 199969380.

The previous prime is 199997797. The next prime is 199997851. The reversal of 199997849 is 948799991.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 199997849 - 2⁸ = 199997593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199997869) 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, 4682 + ... + 20540.

It is an arithmetic number, because the mean of its divisors is an integer number (50006580).

Almost surely, 2^199997849 is an apocalyptic number.

It is an amenable number.

199997849 is a deficient number, since it is larger than the sum of its proper divisors (28471).

199997849 is a wasteful number, since it uses less digits than its factorization.

199997849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28470.

The product of its digits is 13226976, while the sum is 65.

The square root of 199997849 is about 14142.0595741922. The cubic root of 199997849 is about 584.8014511143.

The spelling of 199997849 in words is "one hundred ninety-nine million, nine hundred ninety-seven thousand, eight hundred forty-nine".