191023211231 has 2 divisors, whose sum is σ = 191023211232. Its totient is φ = 191023211230.

The previous prime is 191023211227. The next prime is 191023211261. The reversal of 191023211231 is 132112320191.

It is a weak prime.

It is an emirp because it is prime and its reverse (132112320191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191023211231 - 2² = 191023211227 is a prime.

It is a super-2 number, since 2×191023211231² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 191023211231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191023211261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95511605615 + 95511605616.

It is an arithmetic number, because the mean of its divisors is an integer number (95511605616).

Almost surely, 2^191023211231 is an apocalyptic number.

191023211231 is a deficient number, since it is larger than the sum of its proper divisors (1).

191023211231 is an equidigital number, since it uses as much as digits as its factorization.

191023211231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 26.

The spelling of 191023211231 in words is "one hundred ninety-one billion, twenty-three million, two hundred eleven thousand, two hundred thirty-one".