81729749088 has 288 divisors, whose sum is σ = 260393043456. Its totient is φ = 25067708928.

The previous prime is 81729749081. The next prime is 81729749093. The reversal of 81729749088 is 88094792718.

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

It is a super-3 number, since 3×81729749088³ (a number of 34 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81729749081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 37098195 + ... + 37100397.

It is an arithmetic number, because the mean of its divisors is an integer number (904142512).

Almost surely, 2^81729749088 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 81729749088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130196521728).

81729749088 is an abundant number, since it is smaller than the sum of its proper divisors (178663294368).

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

81729749088 is a wasteful number, since it uses less digits than its factorization.

81729749088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2608 (or 2588 counting only the distinct ones).

The product of its (nonzero) digits is 16257024, while the sum is 63.

The spelling of 81729749088 in words is "eighty-one billion, seven hundred twenty-nine million, seven hundred forty-nine thousand, eighty-eight".