191011111100221 has 2 divisors, whose sum is σ = 191011111100222. Its totient is φ = 191011111100220.

The previous prime is 191011111100197. The next prime is 191011111100263. The reversal of 191011111100221 is 122001111110191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 182952297272196 + 8058813828025 = 13525986^2 + 2838805^2 .

It is an emirp because it is prime and its reverse (122001111110191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191011111100221 - 2¹⁹ = 191011110575933 is a prime.

It is a super-2 number, since 2×191011111100221² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 191011111100192 and 191011111100201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191011111100021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95505555550110 + 95505555550111.

It is an arithmetic number, because the mean of its divisors is an integer number (95505555550111).

Almost surely, 2^{191011111100221} is an apocalyptic number.

It is an amenable number.

191011111100221 is a deficient number, since it is larger than the sum of its proper divisors (1).

191011111100221 is an equidigital number, since it uses as much as digits as its factorization.

191011111100221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 22.

The spelling of 191011111100221 in words is "one hundred ninety-one trillion, eleven billion, one hundred eleven million, one hundred thousand, two hundred twenty-one".