81298265328 has 600 divisors, whose sum is σ = 287602913664. Its totient is φ = 22077619200.

The previous prime is 81298265327. The next prime is 81298265357. The reversal of 81298265328 is 82356289218.

It is a happy number.

81298265328 is a `hidden beast` number, since 8 + 1 + 29 + 82 + 6 + 532 + 8 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81298265327) by changing a digit.

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 119 ways as a sum of consecutive naturals, for example, 120085726 + ... + 120086402.

Almost surely, 2^81298265328 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 81298265328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143801456832).

81298265328 is an abundant number, since it is smaller than the sum of its proper divisors (206304648336).

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

81298265328 is a wasteful number, since it uses less digits than its factorization.

81298265328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803 (or 781 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 54.

The spelling of 81298265328 in words is "eighty-one billion, two hundred ninety-eight million, two hundred sixty-five thousand, three hundred twenty-eight".