161856885 has 16 divisors (see below), whose sum is σ = 259514496. Its totient is φ = 86142528.

The previous prime is 161856857. The next prime is 161856887. The reversal of 161856885 is 588658161.

It is not a de Polignac number, because 161856885 - 2⁷ = 161856757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161856887) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 3774 + ... + 18383.

It is an arithmetic number, because the mean of its divisors is an integer number (16219656).

Almost surely, 2^161856885 is an apocalyptic number.

161856885 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161856885 is a deficient number, since it is larger than the sum of its proper divisors (97657611).

161856885 is a wasteful number, since it uses less digits than its factorization.

161856885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22652.

The product of its digits is 460800, while the sum is 48.

The square root of 161856885 is about 12722.2987309684. The cubic root of 161856885 is about 544.9756014103.

The spelling of 161856885 in words is "one hundred sixty-one million, eight hundred fifty-six thousand, eight hundred eighty-five".