161561710224 has 120 divisors (see below), whose sum is σ = 471880389240. Its totient is φ = 51536572416.

The previous prime is 161561710213. The next prime is 161561710231. The reversal of 161561710224 is 422017165161.

161561710224 is a `hidden beast` number, since 1 + 6 + 1 + 5 + 617 + 10 + 2 + 24 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1296000000 + 160265710224 = 36000^2 + 400332^2 .

It is a super-2 number, since 2×161561710224² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 300702 + ... + 643074.

It is an arithmetic number, because the mean of its divisors is an integer number (3932336577).

Almost surely, 2^161561710224 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 161561710224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235940194620).

161561710224 is an abundant number, since it is smaller than the sum of its proper divisors (310318679016).

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

161561710224 is a wasteful number, since it uses less digits than its factorization.

161561710224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342529 (or 342520 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

Adding to 161561710224 its reverse (422017165161), we get a palindrome (583578875385).

The spelling of 161561710224 in words is "one hundred sixty-one billion, five hundred sixty-one million, seven hundred ten thousand, two hundred twenty-four".