2009191091 has 2 divisors, whose sum is σ = 2009191092. Its totient is φ = 2009191090.

The previous prime is 2009191073. The next prime is 2009191097. The reversal of 2009191091 is 1901919002.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2009191091 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (2009191097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1004595545 + 1004595546.

It is an arithmetic number, because the mean of its divisors is an integer number (1004595546).

Almost surely, 2^2009191091 is an apocalyptic number.

2009191091 is a deficient number, since it is larger than the sum of its proper divisors (1).

2009191091 is an equidigital number, since it uses as much as digits as its factorization.

2009191091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1458, while the sum is 32.

The square root of 2009191091 is about 44824.0012827949. The cubic root of 2009191091 is about 1261.8481091102.

The spelling of 2009191091 in words is "two billion, nine million, one hundred ninety-one thousand, ninety-one".