81868188776 has 32 divisors (see below), whose sum is σ = 167855496480. Its totient is φ = 37124404800.

The previous prime is 81868188769. The next prime is 81868188793. The reversal of 81868188776 is 67788186818.

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 in 7 ways as a sum of consecutive naturals, for example, 1067846 + ... + 1141941.

It is an arithmetic number, because the mean of its divisors is an integer number (5245484265).

Almost surely, 2^81868188776 is an apocalyptic number.

It is an amenable number.

81868188776 is an abundant number, since it is smaller than the sum of its proper divisors (85987307704).

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

81868188776 is a wasteful number, since it uses less digits than its factorization.

81868188776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2210225 (or 2210221 counting only the distinct ones).

The product of its digits is 57802752, while the sum is 68.

The spelling of 81868188776 in words is "eighty-one billion, eight hundred sixty-eight million, one hundred eighty-eight thousand, seven hundred seventy-six".