321904128 has 320 divisors, whose sum is σ = 1099929600. Its totient is φ = 83091456.

The previous prime is 321904127. The next prime is 321904153. The reversal of 321904128 is 821409123.

It is a junction number, because it is equal to n+sod(n) for n = 321904095 and 321904104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321904127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6849001 + ... + 6849047.

It is an arithmetic number, because the mean of its divisors is an integer number (3437280).

Almost surely, 2^321904128 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 321904128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (549964800).

321904128 is an abundant number, since it is smaller than the sum of its proper divisors (778025472).

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

321904128 is an equidigital number, since it uses as much as digits as its factorization.

321904128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102 (or 72 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 321904128 is about 17941.6868772142. The cubic root of 321904128 is about 685.3443687336.

The spelling of 321904128 in words is "three hundred twenty-one million, nine hundred four thousand, one hundred twenty-eight".