81065916769 has 2 divisors, whose sum is σ = 81065916770. Its totient is φ = 81065916768.

The previous prime is 81065916761. The next prime is 81065916787. The reversal of 81065916769 is 96761956018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 41570316544 + 39495600225 = 203888^2 + 198735^2 .

It is a cyclic number.

It is not a de Polignac number, because 81065916769 - 2³ = 81065916761 is a prime.

It is a super-2 number, since 2×81065916769² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81065916761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40532958384 + 40532958385.

It is an arithmetic number, because the mean of its divisors is an integer number (40532958385).

Almost surely, 2^81065916769 is an apocalyptic number.

It is an amenable number.

81065916769 is a deficient number, since it is larger than the sum of its proper divisors (1).

81065916769 is an equidigital number, since it uses as much as digits as its factorization.

81065916769 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4898880, while the sum is 58.

The spelling of 81065916769 in words is "eighty-one billion, sixty-five million, nine hundred sixteen thousand, seven hundred sixty-nine".