165821785080 has 128 divisors (see below), whose sum is σ = 568749358080. Its totient is φ = 37887621120.

The previous prime is 165821785057. The next prime is 165821785117. The reversal of 165821785080 is 80587128561.

165821785080 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2240832 + ... + 2313648.

It is an arithmetic number, because the mean of its divisors is an integer number (4443354360).

Almost surely, 2^165821785080 is an apocalyptic number.

165821785080 is a gapful number since it is divisible by the number (10) 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 165821785080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (284374679040).

165821785080 is an abundant number, since it is smaller than the sum of its proper divisors (402927573000).

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

165821785080 is a wasteful number, since it uses less digits than its factorization.

165821785080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75549 (or 75545 counting only the distinct ones).

The product of its (nonzero) digits is 1075200, while the sum is 51.

The spelling of 165821785080 in words is "one hundred sixty-five billion, eight hundred twenty-one million, seven hundred eighty-five thousand, eighty".