91329281 has 2 divisors, whose sum is σ = 91329282. Its totient is φ = 91329280.

The previous prime is 91329221. The next prime is 91329289. The reversal of 91329281 is 18292319.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83539600 + 7789681 = 9140^2 + 2791^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91329281 is a prime.

It is a super-2 number, since 2×91329281² = 16682075135953922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (91329289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45664640 + 45664641.

It is an arithmetic number, because the mean of its divisors is an integer number (45664641).

Almost surely, 2^91329281 is an apocalyptic number.

It is an amenable number.

91329281 is a deficient number, since it is larger than the sum of its proper divisors (1).

91329281 is an equidigital number, since it uses as much as digits as its factorization.

91329281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 91329281 is about 9556.6354435021. The cubic root of 91329281 is about 450.3360140571.

The spelling of 91329281 in words is "ninety-one million, three hundred twenty-nine thousand, two hundred eighty-one".