161755559728 has 120 divisors (see below), whose sum is σ = 385122880320. Its totient is φ = 65441416320.

The previous prime is 161755559723. The next prime is 161755559741. The reversal of 161755559728 is 827955557161.

161755559728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×161755559728² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161755559723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4196383 + ... + 4234753.

It is an arithmetic number, because the mean of its divisors is an integer number (3209357336).

Almost surely, 2^161755559728 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 161755559728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192561440160).

161755559728 is an abundant number, since it is smaller than the sum of its proper divisors (223367320592).

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

161755559728 is a wasteful number, since it uses less digits than its factorization.

161755559728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38695 (or 38682 counting only the distinct ones).

The product of its digits is 26460000, while the sum is 61.

The spelling of 161755559728 in words is "one hundred sixty-one billion, seven hundred fifty-five million, five hundred fifty-nine thousand, seven hundred twenty-eight".