81355630637500 has 72 divisors (see below), whose sum is σ = 178032611839824. Its totient is φ = 32527886160000.

The previous prime is 81355630637497. The next prime is 81355630637507. The reversal of 81355630637500 is 573603655318.

81355630637500 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81355630637507) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26902024 + ... + 29772976.

It is an arithmetic number, because the mean of its divisors is an integer number (2472675164442).

Almost surely, 2^{81355630637500} 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 81355630637500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89016305919912).

81355630637500 is an abundant number, since it is smaller than the sum of its proper divisors (96676981202324).

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

81355630637500 is a wasteful number, since it uses less digits than its factorization.

81355630637500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2873249 (or 2873227 counting only the distinct ones).

The product of its (nonzero) digits is 6804000, while the sum is 52.

The spelling of 81355630637500 in words is "eighty-one trillion, three hundred fifty-five billion, six hundred thirty million, six hundred thirty-seven thousand, five hundred".