81935510912579 has 2 divisors, whose sum is σ = 81935510912580. Its totient is φ = 81935510912578.

The previous prime is 81935510912531. The next prime is 81935510912683. The reversal of 81935510912579 is 97521901553918.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81935510912579 is a prime.

It is not a weakly prime, because it can be changed into another prime (81935510912779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40967755456289 + 40967755456290.

It is an arithmetic number, because the mean of its divisors is an integer number (40967755456290).

Almost surely, 2^{81935510912579} is an apocalyptic number.

81935510912579 is a deficient number, since it is larger than the sum of its proper divisors (1).

81935510912579 is an equidigital number, since it uses as much as digits as its factorization.

81935510912579 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30618000, while the sum is 65.

The spelling of 81935510912579 in words is "eighty-one trillion, nine hundred thirty-five billion, five hundred ten million, nine hundred twelve thousand, five hundred seventy-nine".