191491193 has 2 divisors, whose sum is σ = 191491194. Its totient is φ = 191491192.

The previous prime is 191491171. The next prime is 191491211. The reversal of 191491193 is 391194191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190798969 + 692224 = 13813^2 + 832^2 .

It is a cyclic number.

It is not a de Polignac number, because 191491193 - 2¹⁴ = 191474809 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (191491093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95745596 + 95745597.

It is an arithmetic number, because the mean of its divisors is an integer number (95745597).

Almost surely, 2^191491193 is an apocalyptic number.

It is an amenable number.

191491193 is a deficient number, since it is larger than the sum of its proper divisors (1).

191491193 is an equidigital number, since it uses as much as digits as its factorization.

191491193 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 38.

The square root of 191491193 is about 13838.0342895947. The cubic root of 191491193 is about 576.3897754454.

The spelling of 191491193 in words is "one hundred ninety-one million, four hundred ninety-one thousand, one hundred ninety-three".