81021826696 has 8 divisors (see below), whose sum is σ = 151915925070. Its totient is φ = 40510913344.

The previous prime is 81021826679. The next prime is 81021826709. The reversal of 81021826696 is 69662812018.

It can be written as a sum of positive squares in only one way, i.e., 46902564900 + 34119261796 = 216570^2 + 184714^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5063864161 + ... + 5063864176.

Almost surely, 2^81021826696 is an apocalyptic number.

It is an amenable number.

81021826696 is a deficient number, since it is larger than the sum of its proper divisors (70894098374).

81021826696 is a wasteful number, since it uses less digits than its factorization.

81021826696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10127728343 (or 10127728339 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 49.

The spelling of 81021826696 in words is "eighty-one billion, twenty-one million, eight hundred twenty-six thousand, six hundred ninety-six".