91171321 has 2 divisors, whose sum is σ = 91171322. Its totient is φ = 91171320.

The previous prime is 91171277. The next prime is 91171361. The reversal of 91171321 is 12317119.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68475625 + 22695696 = 8275^2 + 4764^2 .

It is an emirp because it is prime and its reverse (12317119) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91171321 - 2¹⁹ = 90647033 is a prime.

It is not a weakly prime, because it can be changed into another prime (91171361) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45585660 + 45585661.

It is an arithmetic number, because the mean of its divisors is an integer number (45585661).

Almost surely, 2^91171321 is an apocalyptic number.

It is an amenable number.

91171321 is a deficient number, since it is larger than the sum of its proper divisors (1).

91171321 is an equidigital number, since it uses as much as digits as its factorization.

91171321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 378, while the sum is 25.

The square root of 91171321 is about 9548.3674520831. The cubic root of 91171321 is about 450.0762356437.

The spelling of 91171321 in words is "ninety-one million, one hundred seventy-one thousand, three hundred twenty-one".