81338333760 has 280 divisors, whose sum is σ = 289661803200. Its totient is φ = 21665719296.

The previous prime is 81338333723. The next prime is 81338333833. The reversal of 81338333760 is 6733383318.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 44037157 + ... + 44039003.

It is an arithmetic number, because the mean of its divisors is an integer number (1034506440).

Almost surely, 2^81338333760 is an apocalyptic number.

81338333760 is a gapful number since it is divisible by the number (80) 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 81338333760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144830901600).

81338333760 is an abundant number, since it is smaller than the sum of its proper divisors (208323469440).

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

81338333760 is a wasteful number, since it uses less digits than its factorization.

81338333760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3575 (or 3556 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 45.

The spelling of 81338333760 in words is "eighty-one billion, three hundred thirty-eight million, three hundred thirty-three thousand, seven hundred sixty".