163891728 has 320 divisors, whose sum is σ = 633292800. Its totient is φ = 39191040.

The previous prime is 163891709. The next prime is 163891729. The reversal of 163891728 is 827198361.

163891728 is a `hidden beast` number, since 1 + 638 + 9 + 1 + 7 + 2 + 8 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163891729) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 432243 + ... + 432621.

It is an arithmetic number, because the mean of its divisors is an integer number (1979040).

Almost surely, 2^163891728 is an apocalyptic number.

163891728 is a gapful number since it is divisible by the number (18) 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 163891728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (316646400).

163891728 is an abundant number, since it is smaller than the sum of its proper divisors (469401072).

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

163891728 is a wasteful number, since it uses less digits than its factorization.

163891728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427 (or 415 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 163891728 is about 12802.0204655359. The cubic root of 163891728 is about 547.2498838796.

The spelling of 163891728 in words is "one hundred sixty-three million, eight hundred ninety-one thousand, seven hundred twenty-eight".