91068821 has 2 divisors, whose sum is σ = 91068822. Its totient is φ = 91068820.

The previous prime is 91068811. The next prime is 91068829. The reversal of 91068821 is 12886019.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69072721 + 21996100 = 8311^2 + 4690^2 .

It is an emirp because it is prime and its reverse (12886019) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91068821 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 (91068829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45534410 + 45534411.

It is an arithmetic number, because the mean of its divisors is an integer number (45534411).

Almost surely, 2^91068821 is an apocalyptic number.

It is an amenable number.

91068821 is a deficient number, since it is larger than the sum of its proper divisors (1).

91068821 is an equidigital number, since it uses as much as digits as its factorization.

91068821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 91068821 is about 9542.9985329560. The cubic root of 91068821 is about 449.9075052694.

The spelling of 91068821 in words is "ninety-one million, sixty-eight thousand, eight hundred twenty-one".