81359876840839 has 2 divisors, whose sum is σ = 81359876840840. Its totient is φ = 81359876840838.

The previous prime is 81359876840831. The next prime is 81359876840849. The reversal of 81359876840839 is 93804867895318.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81359876840839 - 2³ = 81359876840831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81359876840831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40679938420419 + 40679938420420.

It is an arithmetic number, because the mean of its divisors is an integer number (40679938420420).

Almost surely, 2^{81359876840839} is an apocalyptic number.

81359876840839 is a deficient number, since it is larger than the sum of its proper divisors (1).

81359876840839 is an equidigital number, since it uses as much as digits as its factorization.

81359876840839 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2508226560, while the sum is 79.

The spelling of 81359876840839 in words is "eighty-one trillion, three hundred fifty-nine billion, eight hundred seventy-six million, eight hundred forty thousand, eight hundred thirty-nine".