161804265728 has 162 divisors, whose sum is σ = 399116737026. Its totient is φ = 65264123904.

The previous prime is 161804265713. The next prime is 161804265757. The reversal of 161804265728 is 827562408161.

It can be written as a sum of positive squares in 3 ways, for example, as 100038098944 + 61766166784 = 316288^2 + 248528^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3602900 + ... + 3647532.

Almost surely, 2^161804265728 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 161804265728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (199558368513).

161804265728 is an abundant number, since it is smaller than the sum of its proper divisors (237312471298).

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

161804265728 is an equidigital number, since it uses as much as digits as its factorization.

161804265728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44697 (or 44659 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 50.

The spelling of 161804265728 in words is "one hundred sixty-one billion, eight hundred four million, two hundred sixty-five thousand, seven hundred twenty-eight".