81527744988 has 72 divisors (see below), whose sum is σ = 209232004800. Its totient is φ = 26762576256.

The previous prime is 81527744941. The next prime is 81527744989. The reversal of 81527744988 is 88944772518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81527744989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1069470 + ... + 1143162.

Almost surely, 2^81527744988 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81527744988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104616002400).

81527744988 is an abundant number, since it is smaller than the sum of its proper divisors (127704259812).

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

81527744988 is a wasteful number, since it uses less digits than its factorization.

81527744988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74171 (or 74166 counting only the distinct ones).

The product of its digits is 36126720, while the sum is 63.

The spelling of 81527744988 in words is "eighty-one billion, five hundred twenty-seven million, seven hundred forty-four thousand, nine hundred eighty-eight".