71986761639 has 16 divisors (see below), whose sum is σ = 114850674400. Its totient is φ = 44299545408.

The previous prime is 71986761601. The next prime is 71986761643. The reversal of 71986761639 is 93616768917.

71986761639 is a `hidden beast` number, since 7 + 1 + 9 + 8 + 6 + 7 + 616 + 3 + 9 = 666.

It is not a de Polignac number, because 71986761639 - 2⁹ = 71986761127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71986761739) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 102544894 + ... + 102545595.

It is an arithmetic number, because the mean of its divisors is an integer number (7178167150).

Almost surely, 2^71986761639 is an apocalyptic number.

71986761639 is a deficient number, since it is larger than the sum of its proper divisors (42863912761).

71986761639 is a wasteful number, since it uses less digits than its factorization.

71986761639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205090511 (or 205090505 counting only the distinct ones).

The product of its digits is 20575296, while the sum is 63.

The spelling of 71986761639 in words is "seventy-one billion, nine hundred eighty-six million, seven hundred sixty-one thousand, six hundred thirty-nine".