191027491 has 2 divisors, whose sum is σ = 191027492. Its totient is φ = 191027490.

The previous prime is 191027477. The next prime is 191027497. The reversal of 191027491 is 194720191.

191027491 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 is an emirp because it is prime and its reverse (194720191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191027491 - 2¹⁵ = 190994723 is a prime.

It is not a weakly prime, because it can be changed into another prime (191027497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95513745 + 95513746.

It is an arithmetic number, because the mean of its divisors is an integer number (95513746).

Almost surely, 2^191027491 is an apocalyptic number.

191027491 is a deficient number, since it is larger than the sum of its proper divisors (1).

191027491 is an equidigital number, since it uses as much as digits as its factorization.

191027491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 34.

The square root of 191027491 is about 13821.2695147732. The cubic root of 191027491 is about 575.9241506911.

The spelling of 191027491 in words is "one hundred ninety-one million, twenty-seven thousand, four hundred ninety-one".