81913564876 has 24 divisors (see below), whose sum is σ = 168409707984. Its totient is φ = 34369327680.

The previous prime is 81913564871. The next prime is 81913564897. The reversal of 81913564876 is 67846531918.

It is a super-2 number, since 2×81913564876² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81913564876.

It is not an unprimeable number, because it can be changed into a prime (81913564871) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 71602195 + ... + 71603338.

It is an arithmetic number, because the mean of its divisors is an integer number (7017071166).

Almost surely, 2^81913564876 is an apocalyptic number.

It is an amenable number.

81913564876 is an abundant number, since it is smaller than the sum of its proper divisors (86496143108).

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

81913564876 is a wasteful number, since it uses less digits than its factorization.

81913564876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143205561 (or 143205559 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 58.

The spelling of 81913564876 in words is "eighty-one billion, nine hundred thirteen million, five hundred sixty-four thousand, eight hundred seventy-six".