91038821 has 2 divisors, whose sum is σ = 91038822. Its totient is φ = 91038820.

The previous prime is 91038817. The next prime is 91038839. The reversal of 91038821 is 12883019.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88830625 + 2208196 = 9425^2 + 1486^2 .

It is a cyclic number.

It is not a de Polignac number, because 91038821 - 2² = 91038817 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91038841) 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, 45519410 + 45519411.

It is an arithmetic number, because the mean of its divisors is an integer number (45519411).

Almost surely, 2^91038821 is an apocalyptic number.

It is an amenable number.

91038821 is a deficient number, since it is larger than the sum of its proper divisors (1).

91038821 is an equidigital number, since it uses as much as digits as its factorization.

91038821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 91038821 is about 9541.4265704872. The cubic root of 91038821 is about 449.8580968207.

The spelling of 91038821 in words is "ninety-one million, thirty-eight thousand, eight hundred twenty-one".