81736522577 has 2 divisors, whose sum is σ = 81736522578. Its totient is φ = 81736522576.

The previous prime is 81736522559. The next prime is 81736522607. The reversal of 81736522577 is 77522563718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70480161361 + 11256361216 = 265481^2 + 106096^2 .

It is a cyclic number.

It is not a de Polignac number, because 81736522577 - 2³² = 77441555281 is a prime.

It is not a weakly prime, because it can be changed into another prime (81736522537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40868261288 + 40868261289.

It is an arithmetic number, because the mean of its divisors is an integer number (40868261289).

Almost surely, 2^81736522577 is an apocalyptic number.

It is an amenable number.

81736522577 is a deficient number, since it is larger than the sum of its proper divisors (1).

81736522577 is an equidigital number, since it uses as much as digits as its factorization.

81736522577 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4939200, while the sum is 53.

The spelling of 81736522577 in words is "eighty-one billion, seven hundred thirty-six million, five hundred twenty-two thousand, five hundred seventy-seven".