81346691839573 has 2 divisors, whose sum is σ = 81346691839574. Its totient is φ = 81346691839572.

The previous prime is 81346691839547. The next prime is 81346691839639. The reversal of 81346691839573 is 37593819664318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71221835125809 + 10124856713764 = 8439303^2 + 3181958^2 .

It is a cyclic number.

It is not a de Polignac number, because 81346691839573 - 2⁴¹ = 79147668584021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81346691839496 and 81346691839505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81346691839073) 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, 40673345919786 + 40673345919787.

It is an arithmetic number, because the mean of its divisors is an integer number (40673345919787).

Almost surely, 2^{81346691839573} is an apocalyptic number.

It is an amenable number.

81346691839573 is a deficient number, since it is larger than the sum of its proper divisors (1).

81346691839573 is an equidigital number, since it uses as much as digits as its factorization.

81346691839573 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 705438720, while the sum is 73.

The spelling of 81346691839573 in words is "eighty-one trillion, three hundred forty-six billion, six hundred ninety-one million, eight hundred thirty-nine thousand, five hundred seventy-three".