81772342559 has 2 divisors, whose sum is σ = 81772342560. Its totient is φ = 81772342558.

The previous prime is 81772342489. The next prime is 81772342571. The reversal of 81772342559 is 95524327718.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81772342559 - 2³² = 77477375263 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81772342559.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81772342859) 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, 40886171279 + 40886171280.

It is an arithmetic number, because the mean of its divisors is an integer number (40886171280).

Almost surely, 2^81772342559 is an apocalyptic number.

81772342559 is a deficient number, since it is larger than the sum of its proper divisors (1).

81772342559 is an equidigital number, since it uses as much as digits as its factorization.

81772342559 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4233600, while the sum is 53.

The spelling of 81772342559 in words is "eighty-one billion, seven hundred seventy-two million, three hundred forty-two thousand, five hundred fifty-nine".