81337617792 has 48 divisors (see below), whose sum is σ = 234057471180. Its totient is φ = 27112538880.

The previous prime is 81337617773. The next prime is 81337617799. The reversal of 81337617792 is 29771673318.

81337617792 is a `hidden beast` number, since 8 + 13 + 3 + 7 + 617 + 7 + 9 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81337617799) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35301634 + ... + 35303937.

Almost surely, 2^81337617792 is an apocalyptic number.

It is an amenable number.

81337617792 is an abundant number, since it is smaller than the sum of its proper divisors (152719853388).

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

81337617792 is a wasteful number, since it uses less digits than its factorization.

81337617792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70605591 (or 70605576 counting only the distinct ones).

The product of its digits is 2667168, while the sum is 54.

The spelling of 81337617792 in words is "eighty-one billion, three hundred thirty-seven million, six hundred seventeen thousand, seven hundred ninety-two".