191638193 has 2 divisors, whose sum is σ = 191638194. Its totient is φ = 191638192.

The previous prime is 191638171. The next prime is 191638201. The reversal of 191638193 is 391836191.

191638193 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 101445184 + 90193009 = 10072^2 + 9497^2 .

It is a cyclic number.

It is not a de Polignac number, because 191638193 - 2¹⁰ = 191637169 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 191638193.

It is not a weakly prime, because it can be changed into another prime (191638103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95819096 + 95819097.

It is an arithmetic number, because the mean of its divisors is an integer number (95819097).

Almost surely, 2^191638193 is an apocalyptic number.

It is an amenable number.

191638193 is a deficient number, since it is larger than the sum of its proper divisors (1).

191638193 is an equidigital number, since it uses as much as digits as its factorization.

191638193 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 41.

The square root of 191638193 is about 13843.3447186726. The cubic root of 191638193 is about 576.5372280494.

The spelling of 191638193 in words is "one hundred ninety-one million, six hundred thirty-eight thousand, one hundred ninety-three".