191495221 has 2 divisors, whose sum is σ = 191495222. Its totient is φ = 191495220.

The previous prime is 191495203. The next prime is 191495261. The reversal of 191495221 is 122594191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 184280625 + 7214596 = 13575^2 + 2686^2 .

It is a cyclic number.

It is not a de Polignac number, because 191495221 - 2⁵ = 191495189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191495261) 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, 95747610 + 95747611.

It is an arithmetic number, because the mean of its divisors is an integer number (95747611).

Almost surely, 2^191495221 is an apocalyptic number.

It is an amenable number.

191495221 is a deficient number, since it is larger than the sum of its proper divisors (1).

191495221 is an equidigital number, since it uses as much as digits as its factorization.

191495221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 34.

The square root of 191495221 is about 13838.1798297319. The cubic root of 191495221 is about 576.3938168528.

The spelling of 191495221 in words is "one hundred ninety-one million, four hundred ninety-five thousand, two hundred twenty-one".