81976647168 has 120 divisors (see below), whose sum is σ = 254789583048. Its totient is φ = 25223565312.

The previous prime is 81976647157. The next prime is 81976647187. The reversal of 81976647168 is 86174667918.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

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 11 ways as a sum of consecutive naturals, for example, 624330 + ... + 744137.

Almost surely, 2^81976647168 is an apocalyptic number.

It is an amenable number.

81976647168 is an abundant number, since it is smaller than the sum of its proper divisors (172812935880).

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

81976647168 is a wasteful number, since it uses less digits than its factorization.

81976647168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1368504 (or 1368485 counting only the distinct ones).

The product of its digits is 24385536, while the sum is 63.

The spelling of 81976647168 in words is "eighty-one billion, nine hundred seventy-six million, six hundred forty-seven thousand, one hundred sixty-eight".