918191909191 has 4 divisors (see below), whose sum is σ = 918921213000. Its totient is φ = 917462605384.

The previous prime is 918191909161. The next prime is 918191909227. The reversal of 918191909191 is 191909191819.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 191909191819 = 6091 ⋅31507009.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-918191909191 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (918191909161) 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 3 ways as a sum of consecutive naturals, for example, 364650016 + ... + 364652533.

It is an arithmetic number, because the mean of its divisors is an integer number (229730303250).

Almost surely, 2^918191909191 is an apocalyptic number.

918191909191 is a deficient number, since it is larger than the sum of its proper divisors (729303809).

918191909191 is a wasteful number, since it uses less digits than its factorization.

918191909191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 729303808.

The product of its (nonzero) digits is 472392, while the sum is 58.

The spelling of 918191909191 in words is "nine hundred eighteen billion, one hundred ninety-one million, nine hundred nine thousand, one hundred ninety-one".