191291101 has 2 divisors, whose sum is σ = 191291102. Its totient is φ = 191291100.

The previous prime is 191291063. The next prime is 191291129. The reversal of 191291101 is 101192191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 191268900 + 22201 = 13830^2 + 149^2 .

It is an emirp because it is prime and its reverse (101192191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191291101 - 2¹¹ = 191289053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191291131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95645550 + 95645551.

It is an arithmetic number, because the mean of its divisors is an integer number (95645551).

Almost surely, 2^191291101 is an apocalyptic number.

It is an amenable number.

191291101 is a deficient number, since it is larger than the sum of its proper divisors (1).

191291101 is an equidigital number, since it uses as much as digits as its factorization.

191291101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 25.

The square root of 191291101 is about 13830.8026159005. The cubic root of 191291101 is about 576.1889460586.

The spelling of 191291101 in words is "one hundred ninety-one million, two hundred ninety-one thousand, one hundred one".