81125129088 has 288 divisors, whose sum is σ = 243540161280. Its totient is φ = 25918341120.

The previous prime is 81125129083. The next prime is 81125129143. The reversal of 81125129088 is 88092152118.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81125129081) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 140597856 + ... + 140598432.

It is an arithmetic number, because the mean of its divisors is an integer number (845625560).

Almost surely, 2^81125129088 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 81125129088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121770080640).

81125129088 is an abundant number, since it is smaller than the sum of its proper divisors (162415032192).

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

81125129088 is a wasteful number, since it uses less digits than its factorization.

81125129088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 786 (or 740 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 45.

The spelling of 81125129088 in words is "eighty-one billion, one hundred twenty-five million, one hundred twenty-nine thousand, eighty-eight".