81770819328 has 360 divisors, whose sum is σ = 273208929840. Its totient is φ = 24106844160.

The previous prime is 81770819311. The next prime is 81770819341. The reversal of 81770819328 is 82391807718.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8434708 + ... + 8444396.

It is an arithmetic number, because the mean of its divisors is an integer number (758913694).

Almost surely, 2^81770819328 is an apocalyptic number.

81770819328 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81770819328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136604464920).

81770819328 is an abundant number, since it is smaller than the sum of its proper divisors (191438110512).

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

81770819328 is a wasteful number, since it uses less digits than its factorization.

81770819328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9765 (or 9742 counting only the distinct ones).

The product of its (nonzero) digits is 1354752, while the sum is 54.

The spelling of 81770819328 in words is "eighty-one billion, seven hundred seventy million, eight hundred nineteen thousand, three hundred twenty-eight".