81328435200 has 936 divisors, whose sum is σ = 320854575600. Its totient is φ = 19597885440.

The previous prime is 81328435193. The next prime is 81328435213. The reversal of 81328435200 is 253482318.

81328435200 is a `hidden beast` number, since 8 + 13 + 2 + 8 + 435 + 200 = 666.

It is a super-2 number, since 2×81328435200² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 454348711 + ... + 454348889.

It is an arithmetic number, because the mean of its divisors is an integer number (342793350).

Almost surely, 2^81328435200 is an apocalyptic number.

81328435200 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 81328435200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160427287800).

81328435200 is an abundant number, since it is smaller than the sum of its proper divisors (239526140400).

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

81328435200 is a wasteful number, since it uses less digits than its factorization.

81328435200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The spelling of 81328435200 in words is "eighty-one billion, three hundred twenty-eight million, four hundred thirty-five thousand, two hundred".