91211211122201 has 2 divisors, whose sum is σ = 91211211122202. Its totient is φ = 91211211122200.

The previous prime is 91211211122173. The next prime is 91211211122209. The reversal of 91211211122201 is 10222111211219.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83737964214025 + 7473246908176 = 9150845^2 + 2733724^2 .

It is an emirp because it is prime and its reverse (10222111211219) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91211211122201 is a prime.

It is not a weakly prime, because it can be changed into another prime (91211211122209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45605605561100 + 45605605561101.

It is an arithmetic number, because the mean of its divisors is an integer number (45605605561101).

Almost surely, 2^{91211211122201} is an apocalyptic number.

It is an amenable number.

91211211122201 is a deficient number, since it is larger than the sum of its proper divisors (1).

91211211122201 is an equidigital number, since it uses as much as digits as its factorization.

91211211122201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 26.

The spelling of 91211211122201 in words is "ninety-one trillion, two hundred eleven billion, two hundred eleven million, one hundred twenty-two thousand, two hundred one".