71681535613 has 2 divisors, whose sum is σ = 71681535614. Its totient is φ = 71681535612.

The previous prime is 71681535593. The next prime is 71681535641. The reversal of 71681535613 is 31653518617.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71619393924 + 62141689 = 267618^2 + 7883^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71681535613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71681535313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35840767806 + 35840767807.

It is an arithmetic number, because the mean of its divisors is an integer number (35840767807).

Almost surely, 2^71681535613 is an apocalyptic number.

It is an amenable number.

71681535613 is a deficient number, since it is larger than the sum of its proper divisors (1).

71681535613 is an equidigital number, since it uses as much as digits as its factorization.

71681535613 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 453600, while the sum is 46.

The spelling of 71681535613 in words is "seventy-one billion, six hundred eighty-one million, five hundred thirty-five thousand, six hundred thirteen".