199168861991 has 8 divisors (see below), whose sum is σ = 217353679104. Its totient is φ = 180997137720.

The previous prime is 199168861981. The next prime is 199168861999.

199168861991 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199168861991 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 (199168861999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3241385 + ... + 3302258.

It is an arithmetic number, because the mean of its divisors is an integer number (27169209888).

Almost surely, 2^199168861991 is an apocalyptic number.

199168861991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

199168861991 is a deficient number, since it is larger than the sum of its proper divisors (18184817113).

199168861991 is a wasteful number, since it uses less digits than its factorization.

199168861991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6546421.

The product of its digits is 15116544, while the sum is 68.

The spelling of 199168861991 in words is "one hundred ninety-nine billion, one hundred sixty-eight million, eight hundred sixty-one thousand, nine hundred ninety-one".