91522877821 has 2 divisors, whose sum is σ = 91522877822. Its totient is φ = 91522877820.

The previous prime is 91522877819. The next prime is 91522877827. The reversal of 91522877821 is 12877822519.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87098765625 + 4424112196 = 295125^2 + 66514^2 .

It is an emirp because it is prime and its reverse (12877822519) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91522877821 - 2¹ = 91522877819 is a prime.

Together with 91522877819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91522877827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45761438910 + 45761438911.

It is an arithmetic number, because the mean of its divisors is an integer number (45761438911).

Almost surely, 2^91522877821 is an apocalyptic number.

It is an amenable number.

91522877821 is a deficient number, since it is larger than the sum of its proper divisors (1).

91522877821 is an equidigital number, since it uses as much as digits as its factorization.

91522877821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1128960, while the sum is 52.

The spelling of 91522877821 in words is "ninety-one billion, five hundred twenty-two million, eight hundred seventy-seven thousand, eight hundred twenty-one".