191587191317 has 4 divisors (see below), whose sum is σ = 198193646220. Its totient is φ = 184980736416.

The previous prime is 191587191269. The next prime is 191587191337. The reversal of 191587191317 is 713191785191.

191587191317 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 145123664401 + 46463526916 = 380951^2 + 215554^2 .

It is a cyclic number.

It is not a de Polignac number, because 191587191317 - 2¹⁸ = 191586929173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191587191337) 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 in 3 ways as a sum of consecutive naturals, for example, 3303227408 + ... + 3303227465.

It is an arithmetic number, because the mean of its divisors is an integer number (49548411555).

Almost surely, 2^191587191317 is an apocalyptic number.

It is an amenable number.

191587191317 is a deficient number, since it is larger than the sum of its proper divisors (6606454903).

191587191317 is an equidigital number, since it uses as much as digits as its factorization.

191587191317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6606454902.

The product of its digits is 476280, while the sum is 53.

The spelling of 191587191317 in words is "one hundred ninety-one billion, five hundred eighty-seven million, one hundred ninety-one thousand, three hundred seventeen".