191910019091 has 16 divisors (see below), whose sum is σ = 219772949760. Its totient is φ = 164159086560.

The previous prime is 191910019073. The next prime is 191910019111. The reversal of 191910019091 is 190910019191.

It is a happy number.

It is not a de Polignac number, because 191910019091 - 2¹⁴ = 191910002707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (191910019051) 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, 16508261 + ... + 16519881.

It is an arithmetic number, because the mean of its divisors is an integer number (13735809360).

Almost surely, 2^191910019091 is an apocalyptic number.

191910019091 is a deficient number, since it is larger than the sum of its proper divisors (27862930669).

191910019091 is a wasteful number, since it uses less digits than its factorization.

191910019091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16234.

The product of its (nonzero) digits is 6561, while the sum is 41.

The spelling of 191910019091 in words is "one hundred ninety-one billion, nine hundred ten million, nineteen thousand, ninety-one".