909191919091 has 4 divisors (see below), whose sum is σ = 909220945312. Its totient is φ = 909162892872.

The previous prime is 909191919043. The next prime is 909191919107. The reversal of 909191919091 is 190919191909.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190919191909 = 499 ⋅382603591.

It is a cyclic number.

It is not a de Polignac number, because 909191919091 - 2¹¹ = 909191917043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (909191919001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14466075 + ... + 14528788.

It is an arithmetic number, because the mean of its divisors is an integer number (227305236328).

Almost surely, 2^909191919091 is an apocalyptic number.

909191919091 is a deficient number, since it is larger than the sum of its proper divisors (29026221).

909191919091 is a wasteful number, since it uses less digits than its factorization.

909191919091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29026220.

The product of its (nonzero) digits is 531441, while the sum is 58.

The spelling of 909191919091 in words is "nine hundred nine billion, one hundred ninety-one million, nine hundred nineteen thousand, ninety-one".