163681920 has 192 divisors, whose sum is σ = 571956840. Its totient is φ = 43130880.

The previous prime is 163681919. The next prime is 163681939. The reversal of 163681920 is 29186361.

163681920 is a `hidden beast` number, since 1 + 636 + 8 + 19 + 2 + 0 = 666.

163681920 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 61591104 + 102090816 = 7848^2 + 10104^2 .

It is a tau number, because it is divible by the number of its divisors (192).

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 904230 + ... + 904410.

Almost surely, 2^163681920 is an apocalyptic number.

163681920 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 163681920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (285978420).

163681920 is an abundant number, since it is smaller than the sum of its proper divisors (408274920).

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

163681920 is a wasteful number, since it uses less digits than its factorization.

163681920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363 (or 348 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 163681920 is about 12793.8235098035. The cubic root of 163681920 is about 547.0162612823.

The spelling of 163681920 in words is "one hundred sixty-three million, six hundred eighty-one thousand, nine hundred twenty".