91322381 has 2 divisors, whose sum is σ = 91322382. Its totient is φ = 91322380.

The previous prime is 91322377. The next prime is 91322437. The reversal of 91322381 is 18322319.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55741156 + 35581225 = 7466^2 + 5965^2 .

It is an emirp because it is prime and its reverse (18322319) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91322381 - 2² = 91322377 is a prime.

It is a super-4 number, since 4×91322381⁴ (a number of 33 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91322981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45661190 + 45661191.

It is an arithmetic number, because the mean of its divisors is an integer number (45661191).

Almost surely, 2^91322381 is an apocalyptic number.

It is an amenable number.

91322381 is a deficient number, since it is larger than the sum of its proper divisors (1).

91322381 is an equidigital number, since it uses as much as digits as its factorization.

91322381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 29.

The square root of 91322381 is about 9556.2744309694. The cubic root of 91322381 is about 450.3246726899.

The spelling of 91322381 in words is "ninety-one million, three hundred twenty-two thousand, three hundred eighty-one".