71813497728 has 128 divisors (see below), whose sum is σ = 223897605120. Its totient is φ = 19963570176.

The previous prime is 71813497699. The next prime is 71813497741. The reversal of 71813497728 is 82779431817.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×71813497728² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 261576 + ... + 460487.

It is an arithmetic number, because the mean of its divisors is an integer number (1749200040).

Almost surely, 2^71813497728 is an apocalyptic number.

It is an amenable number.

71813497728 is an abundant number, since it is smaller than the sum of its proper divisors (152084107392).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71813497728 is a wasteful number, since it uses less digits than its factorization.

71813497728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 722124 (or 722112 counting only the distinct ones).

The product of its digits is 4741632, while the sum is 57.

The spelling of 71813497728 in words is "seventy-one billion, eight hundred thirteen million, four hundred ninety-seven thousand, seven hundred twenty-eight".