161881285 has 16 divisors (see below), whose sum is σ = 197759232. Its totient is φ = 127192000.

The previous prime is 161881271. The next prime is 161881303. The reversal of 161881285 is 582188161.

It is not a de Polignac number, because 161881285 - 2²⁵ = 128326853 is a prime.

It is a Duffinian number.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 64932 + ... + 67378.

It is an arithmetic number, because the mean of its divisors is an integer number (12359952).

Almost surely, 2^161881285 is an apocalyptic number.

It is an amenable number.

161881285 is a deficient number, since it is larger than the sum of its proper divisors (35877947).

161881285 is a wasteful number, since it uses less digits than its factorization.

161881285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2684.

The product of its digits is 30720, while the sum is 40.

The square root of 161881285 is about 12723.2576410289. The cubic root of 161881285 is about 545.0029851420.

The spelling of 161881285 in words is "one hundred sixty-one million, eight hundred eighty-one thousand, two hundred eighty-five".