163840 has 32 divisors (see below), whose sum is σ = 393210. Its totient is φ = 65536.

The previous prime is 163819. The next prime is 163841. The reversal of 163840 is 48361.

It can be written as a sum of positive squares in only one way, i.e., 147456 + 16384 = 384^2 + 128^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is an ABA number since it can be written as A⋅B^A, here for A=5, B=8.

It is a super-3 number, since 3×163840³ = 13194139533312000, which contains 333 as substring.

It is a nialpdrome in base 4 and base 8.

It is a zygodrome in base 4.

It is not an unprimeable number, because it can be changed into a prime (163841) by changing a digit.

163840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (2) of ones.

In principle, a polygon with 163840 sides can be constructed with ruler and compass.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32766 + ... + 32770.

163840 is a Friedman number, since it can be written as (8*4)^3*(6-1-0), using all its digits and the basic arithmetic operations.

2¹⁶³⁸⁴⁰ is an apocalyptic number.

163840 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 163840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196605).

163840 is an abundant number, since it is smaller than the sum of its proper divisors (229370).

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

163840 is an frugal number, since it uses more digits than its factorization.

163840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35 (or 7 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 163840 is about 404.7715405016. The cubic root of 163840 is about 54.7192302937.

The spelling of 163840 in words is "one hundred sixty-three thousand, eight hundred forty".