81307827656 has 32 divisors (see below), whose sum is σ = 166389893280. Its totient is φ = 36940675200.

The previous prime is 81307827649. The next prime is 81307827661. The reversal of 81307827656 is 65672870318.

It is a super-2 number, since 2×81307827656² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81307827598 and 81307827607.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29261 + ... + 404316.

It is an arithmetic number, because the mean of its divisors is an integer number (5199684165).

Almost surely, 2^81307827656 is an apocalyptic number.

It is an amenable number.

81307827656 is an abundant number, since it is smaller than the sum of its proper divisors (85082065624).

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

81307827656 is a wasteful number, since it uses less digits than its factorization.

81307827656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435725 (or 435721 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 53.

The spelling of 81307827656 in words is "eighty-one billion, three hundred seven million, eight hundred twenty-seven thousand, six hundred fifty-six".