161185920 has 256 divisors, whose sum is σ = 599270400. Its totient is φ = 36089856.

The previous prime is 161185903. The next prime is 161185931. The reversal of 161185920 is 29581161.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 900391 + ... + 900569.

It is an arithmetic number, because the mean of its divisors is an integer number (2340900).

Almost surely, 2^161185920 is an apocalyptic number.

161185920 is a gapful number since it is divisible by the number (10) 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 161185920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (299635200).

161185920 is an abundant number, since it is smaller than the sum of its proper divisors (438084480).

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

161185920 is a wasteful number, since it uses less digits than its factorization.

161185920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275 (or 263 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 33.

The square root of 161185920 is about 12695.9017009427. The cubic root of 161185920 is about 544.2215072564.

The spelling of 161185920 in words is "one hundred sixty-one million, one hundred eighty-five thousand, nine hundred twenty".