161856144 has 100 divisors (see below), whose sum is σ = 475326720. Its totient is φ = 53161920.

The previous prime is 161856137. The next prime is 161856179. The reversal of 161856144 is 441658161.

It is a super-2 number, since 2×161856144² = 52394822701097472, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 161856099 and 161856108.

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 19 ways as a sum of consecutive naturals, for example, 91137 + ... + 92895.

Almost surely, 2^161856144 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 161856144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (237663360).

161856144 is an abundant number, since it is smaller than the sum of its proper divisors (313470576).

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

161856144 is a wasteful number, since it uses less digits than its factorization.

161856144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1850 (or 1835 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 161856144 is about 12722.2696088395. The cubic root of 161856144 is about 544.9747697548.

The spelling of 161856144 in words is "one hundred sixty-one million, eight hundred fifty-six thousand, one hundred forty-four".