91322221 has 2 divisors, whose sum is σ = 91322222. Its totient is φ = 91322220.

The previous prime is 91322219. The next prime is 91322251. The reversal of 91322221 is 12222319.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60918025 + 30404196 = 7805^2 + 5514^2 .

It is an emirp because it is prime and its reverse (12222319) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91322221 - 2¹ = 91322219 is a prime.

Together with 91322219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 91322192 and 91322201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91322201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45661110 + 45661111.

It is an arithmetic number, because the mean of its divisors is an integer number (45661111).

Almost surely, 2^91322221 is an apocalyptic number.

It is an amenable number.

91322221 is a deficient number, since it is larger than the sum of its proper divisors (1).

91322221 is an equidigital number, since it uses as much as digits as its factorization.

91322221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 22.

The square root of 91322221 is about 9556.2660595025. The cubic root of 91322221 is about 450.3244096949.

The spelling of 91322221 in words is "ninety-one million, three hundred twenty-two thousand, two hundred twenty-one".