321304320 has 216 divisors, whose sum is σ = 1153968816. Its totient is φ = 85598208.

The previous prime is 321304289. The next prime is 321304327. The reversal of 321304320 is 23403123.

It is a tau number, because it is divible by the number of its divisors (216).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 321304293 and 321304302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321304327) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 310524 + ... + 311556.

Almost surely, 2^321304320 is an apocalyptic number.

321304320 is a gapful number since it is divisible by the number (30) 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 321304320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (576984408).

321304320 is an abundant number, since it is smaller than the sum of its proper divisors (832664496).

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

321304320 is an equidigital number, since it uses as much as digits as its factorization.

321304320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1069 (or 1043 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

The square root of 321304320 is about 17924.9635982894. The cubic root of 321304320 is about 684.9184338207.

Adding to 321304320 its reverse (23403123), we get a palindrome (344707443).

The spelling of 321304320 in words is "three hundred twenty-one million, three hundred four thousand, three hundred twenty".