191317823 has 2 divisors, whose sum is σ = 191317824. Its totient is φ = 191317822.

The previous prime is 191317817. The next prime is 191317829. The reversal of 191317823 is 328713191.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (191317817) and next prime (191317829).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191317823 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191317829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95658911 + 95658912.

It is an arithmetic number, because the mean of its divisors is an integer number (95658912).

Almost surely, 2^191317823 is an apocalyptic number.

191317823 is a deficient number, since it is larger than the sum of its proper divisors (1).

191317823 is an equidigital number, since it uses as much as digits as its factorization.

191317823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 35.

The square root of 191317823 is about 13831.7686143168. The cubic root of 191317823 is about 576.2157746356.

The spelling of 191317823 in words is "one hundred ninety-one million, three hundred seventeen thousand, eight hundred twenty-three".