199668791 has 16 divisors (see below), whose sum is σ = 243259200. Its totient is φ = 159982080.

The previous prime is 199668769. The next prime is 199668817. The reversal of 199668791 is 197866991.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199668791 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 (199668991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12101 + ... + 23361.

It is an arithmetic number, because the mean of its divisors is an integer number (15203700).

Almost surely, 2^199668791 is an apocalyptic number.

199668791 is a deficient number, since it is larger than the sum of its proper divisors (43590409).

199668791 is a wasteful number, since it uses less digits than its factorization.

199668791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11434.

The product of its digits is 1469664, while the sum is 56.

The square root of 199668791 is about 14130.4207651435. The cubic root of 199668791 is about 584.4805489464.

The spelling of 199668791 in words is "one hundred ninety-nine million, six hundred sixty-eight thousand, seven hundred ninety-one".