81050544065 has 16 divisors (see below), whose sum is σ = 101582372160. Its totient is φ = 62018694720.

The previous prime is 81050544061. The next prime is 81050544079. The reversal of 81050544065 is 56044505018.

It is a happy number.

It is not a de Polignac number, because 81050544065 - 2² = 81050544061 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81050544061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3701891 + ... + 3723720.

It is an arithmetic number, because the mean of its divisors is an integer number (6348898260).

Almost surely, 2^81050544065 is an apocalyptic number.

It is an amenable number.

81050544065 is a deficient number, since it is larger than the sum of its proper divisors (20531828095).

81050544065 is a wasteful number, since it uses less digits than its factorization.

81050544065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7425712.

The product of its (nonzero) digits is 96000, while the sum is 38.

The spelling of 81050544065 in words is "eighty-one billion, fifty million, five hundred forty-four thousand, sixty-five".