321728000 has 160 divisors (see below), whose sum is σ = 877095648. Its totient is φ = 116736000.

The previous prime is 321727993. The next prime is 321728023. The reversal of 321728000 is 827123.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 703772 + ... + 704228.

Almost surely, 2^321728000 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 321728000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (438547824).

321728000 is an abundant number, since it is smaller than the sum of its proper divisors (555367648).

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

321728000 is an equidigital number, since it uses as much as digits as its factorization.

321728000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 501 (or 475 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 321728000 is about 17936.7778600283. Note that the first 3 decimals coincide. The cubic root of 321728000 is about 685.2193518480.

The spelling of 321728000 in words is "three hundred twenty-one million, seven hundred twenty-eight thousand".