81544105636 has 48 divisors (see below), whose sum is σ = 163796484096. Its totient is φ = 34796025504.

The previous prime is 81544105633. The next prime is 81544105711. The reversal of 81544105636 is 63650144518.

It is a junction number, because it is equal to n+sod(n) for n = 81544105592 and 81544105601.

It is not an unprimeable number, because it can be changed into a prime (81544105633) 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, 6503205 + ... + 6515731.

It is an arithmetic number, because the mean of its divisors is an integer number (3412426752).

Almost surely, 2^81544105636 is an apocalyptic number.

It is an amenable number.

81544105636 is an abundant number, since it is smaller than the sum of its proper divisors (82252378460).

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

81544105636 is a wasteful number, since it uses less digits than its factorization.

81544105636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13528 (or 13526 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 43.

The spelling of 81544105636 in words is "eighty-one billion, five hundred forty-four million, one hundred five thousand, six hundred thirty-six".