191198918889 has 12 divisors (see below), whose sum is σ = 301283145072. Its totient is φ = 115878132600.

The previous prime is 191198918887. The next prime is 191198918923. The reversal of 191198918889 is 988819891191.

It is not a de Polignac number, because 191198918889 - 2¹ = 191198918887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (191198918887) 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, 965651007 + ... + 965651204.

It is an arithmetic number, because the mean of its divisors is an integer number (25106928756).

Almost surely, 2^191198918889 is an apocalyptic number.

It is an amenable number.

191198918889 is a deficient number, since it is larger than the sum of its proper divisors (110084226183).

191198918889 is a wasteful number, since it uses less digits than its factorization.

191198918889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1931302228 (or 1931302225 counting only the distinct ones).

The product of its digits is 26873856, while the sum is 72.

The spelling of 191198918889 in words is "one hundred ninety-one billion, one hundred ninety-eight million, nine hundred eighteen thousand, eight hundred eighty-nine".