321251328 has 144 divisors (see below), whose sum is σ = 961424100. Its totient is φ = 103219200.

The previous prime is 321251317. The next prime is 321251339. The reversal of 321251328 is 823152123.

It is an interprime number because it is at equal distance from previous prime (321251317) and next prime (321251339).

It can be written as a sum of positive squares in 2 ways, for example, as 308634624 + 12616704 = 17568^2 + 3552^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 534228 + ... + 534828.

Almost surely, 2^321251328 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 321251328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (480712050).

321251328 is an abundant number, since it is smaller than the sum of its proper divisors (640172772).

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

321251328 is a wasteful number, since it uses less digits than its factorization.

321251328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658 (or 635 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 321251328 is about 17923.4853753393. The cubic root of 321251328 is about 684.8807777307.

The spelling of 321251328 in words is "three hundred twenty-one million, two hundred fifty-one thousand, three hundred twenty-eight".