191992091 has 2 divisors, whose sum is σ = 191992092. Its totient is φ = 191992090.

The previous prime is 191992081. The next prime is 191992127. The reversal of 191992091 is 190299191.

It is a happy number.

191992091 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 191992091 - 2⁶ = 191992027 is a prime.

It is not a weakly prime, because it can be changed into another prime (191992061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95996045 + 95996046.

It is an arithmetic number, because the mean of its divisors is an integer number (95996046).

Almost surely, 2^191992091 is an apocalyptic number.

191992091 is a deficient number, since it is larger than the sum of its proper divisors (1).

191992091 is an equidigital number, since it uses as much as digits as its factorization.

191992091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13122, while the sum is 41.

The square root of 191992091 is about 13856.1210661570. The cubic root of 191992091 is about 576.8919066587.

The spelling of 191992091 in words is "one hundred ninety-one million, nine hundred ninety-two thousand, ninety-one".