1009191111091 has 4 divisors (see below), whose sum is σ = 1009193995800. Its totient is φ = 1009188226384.

The previous prime is 1009191111079. The next prime is 1009191111109. The reversal of 1009191111091 is 1901111919001.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1009191111091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1009191111031) 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, 831301 + ... + 1646038.

It is an arithmetic number, because the mean of its divisors is an integer number (252298498950).

Almost surely, 2^{1009191111091} is an apocalyptic number.

1009191111091 is a deficient number, since it is larger than the sum of its proper divisors (2884709).

1009191111091 is an equidigital number, since it uses as much as digits as its factorization.

1009191111091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2884708.

The product of its (nonzero) digits is 729, while the sum is 34.

The spelling of 1009191111091 in words is "one trillion, nine billion, one hundred ninety-one million, one hundred eleven thousand, ninety-one".