81450043768 has 8 divisors (see below), whose sum is σ = 152718832080. Its totient is φ = 40725021880.

The previous prime is 81450043751. The next prime is 81450043783. The reversal of 81450043768 is 86734005418.

It is a happy number.

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

It is a congruent number.

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, 5090627728 + ... + 5090627743.

It is an arithmetic number, because the mean of its divisors is an integer number (19089854010).

Almost surely, 2^81450043768 is an apocalyptic number.

It is an amenable number.

81450043768 is a deficient number, since it is larger than the sum of its proper divisors (71268788312).

81450043768 is a wasteful number, since it uses less digits than its factorization.

81450043768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10181255477 (or 10181255473 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 46.

The spelling of 81450043768 in words is "eighty-one billion, four hundred fifty million, forty-three thousand, seven hundred sixty-eight".