161685523584 has 384 divisors, whose sum is σ = 532487919600. Its totient is φ = 46650359808.

The previous prime is 161685523561. The next prime is 161685523591. The reversal of 161685523584 is 485325586161.

161685523584 is a `hidden beast` number, since 1 + 6 + 1 + 6 + 8 + 5 + 52 + 3 + 584 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 72447105600 + 89238417984 = 269160^2 + 298728^2 .

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×161685523584² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 161685523584.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 79686282 + ... + 79688310.

Almost surely, 2^161685523584 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 161685523584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266243959800).

161685523584 is an abundant number, since it is smaller than the sum of its proper divisors (370802396016).

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

161685523584 is a wasteful number, since it uses less digits than its factorization.

161685523584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2392 (or 2377 counting only the distinct ones).

The product of its digits is 6912000, while the sum is 54.

The spelling of 161685523584 in words is "one hundred sixty-one billion, six hundred eighty-five million, five hundred twenty-three thousand, five hundred eighty-four".