81787318776 has 48 divisors (see below), whose sum is σ = 221574155400. Its totient is φ = 27254213952.

The previous prime is 81787318751. The next prime is 81787318799. The reversal of 81787318776 is 67781378718.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 71290 + ... + 410678.

Almost surely, 2^81787318776 is an apocalyptic number.

It is an amenable number.

81787318776 is an abundant number, since it is smaller than the sum of its proper divisors (139786836624).

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

81787318776 is a wasteful number, since it uses less digits than its factorization.

81787318776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342748 (or 342741 counting only the distinct ones).

The product of its digits is 22127616, while the sum is 63.

The spelling of 81787318776 in words is "eighty-one billion, seven hundred eighty-seven million, three hundred eighteen thousand, seven hundred seventy-six".