161305992 has 160 divisors (see below), whose sum is σ = 480902400. Its totient is φ = 50409216.

The previous prime is 161305987. The next prime is 161305993. The reversal of 161305992 is 299503161.

161305992 is a `hidden beast` number, since 1 + 61 + 3 + 0 + 599 + 2 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (161305993) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 1177348 + ... + 1177484.

It is an arithmetic number, because the mean of its divisors is an integer number (3005640).

Almost surely, 2^161305992 is an apocalyptic number.

161305992 is a gapful number since it is divisible by the number (12) 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 161305992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (240451200).

161305992 is an abundant number, since it is smaller than the sum of its proper divisors (319596408).

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

161305992 is a wasteful number, since it uses less digits than its factorization.

161305992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 161305992 is about 12700.6295906935. The cubic root of 161305992 is about 544.3566091014.

It can be divided in two parts, 16130 and 5992, that added together give a palindrome (22122).

The spelling of 161305992 in words is "one hundred sixty-one million, three hundred five thousand, nine hundred ninety-two".