918191819091 has 4 divisors (see below), whose sum is σ = 1224255758792. Its totient is φ = 612127879392.

The previous prime is 918191818997. The next prime is 918191819119. The reversal of 918191819091 is 190918191819.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 918191819091 - 2¹⁷ = 918191688019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (918191812091) 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, 153031969846 + ... + 153031969851.

It is an arithmetic number, because the mean of its divisors is an integer number (306063939698).

Almost surely, 2^918191819091 is an apocalyptic number.

918191819091 is a deficient number, since it is larger than the sum of its proper divisors (306063939701).

918191819091 is a wasteful number, since it uses less digits than its factorization.

918191819091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306063939700.

The product of its (nonzero) digits is 419904, while the sum is 57.

The spelling of 918191819091 in words is "nine hundred eighteen billion, one hundred ninety-one million, eight hundred nineteen thousand, ninety-one".