919091919191 has 4 divisors (see below), whose sum is σ = 927225476112. Its totient is φ = 910958362272.

The previous prime is 919091919181. The next prime is 919091919247. The reversal of 919091919191 is 191919190919.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 191919190919 = 60127 ⋅3191897.

It is a cyclic number.

It is not a de Polignac number, because 919091919191 - 2⁶ = 919091919127 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 919091919191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (919091919181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4066778291 + ... + 4066778516.

It is an arithmetic number, because the mean of its divisors is an integer number (231806369028).

Almost surely, 2^919091919191 is an apocalyptic number.

919091919191 is a deficient number, since it is larger than the sum of its proper divisors (8133556921).

919091919191 is a wasteful number, since it uses less digits than its factorization.

919091919191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8133556920.

The product of its (nonzero) digits is 531441, while the sum is 59.

The spelling of 919091919191 in words is "nine hundred nineteen billion, ninety-one million, nine hundred nineteen thousand, one hundred ninety-one".