191017213 has 2 divisors, whose sum is σ = 191017214. Its totient is φ = 191017212.

The previous prime is 191017207. The next prime is 191017243. The reversal of 191017213 is 312710191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 190937124 + 80089 = 13818^2 + 283^2 .

It is an emirp because it is prime and its reverse (312710191) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191017213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191017243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95508606 + 95508607.

It is an arithmetic number, because the mean of its divisors is an integer number (95508607).

Almost surely, 2^191017213 is an apocalyptic number.

It is an amenable number.

191017213 is a deficient number, since it is larger than the sum of its proper divisors (1).

191017213 is an equidigital number, since it uses as much as digits as its factorization.

191017213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 378, while the sum is 25.

The square root of 191017213 is about 13820.8976915394. The cubic root of 191017213 is about 575.9138215415.

The spelling of 191017213 in words is "one hundred ninety-one million, seventeen thousand, two hundred thirteen".