191109192009 has 12 divisors (see below), whose sum is σ = 270682916784. Its totient is φ = 119911649344.

The previous prime is 191109192007. The next prime is 191109192049. The reversal of 191109192009 is 900291901191.

It is not a de Polignac number, because 191109192009 - 2¹ = 191109192007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (191109192007) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 110212047 + ... + 110213780.

It is an arithmetic number, because the mean of its divisors is an integer number (22556909732).

Almost surely, 2^191109192009 is an apocalyptic number.

It is an amenable number.

191109192009 is a deficient number, since it is larger than the sum of its proper divisors (79573724775).

191109192009 is a wasteful number, since it uses less digits than its factorization.

191109192009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220425864 (or 220425847 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 42.

The spelling of 191109192009 in words is "one hundred ninety-one billion, one hundred nine million, one hundred ninety-two thousand, nine".