321216328 has 8 divisors (see below), whose sum is σ = 602280630. Its totient is φ = 160608160.

The previous prime is 321216319. The next prime is 321216341. The reversal of 321216328 is 823612123.

It can be written as a sum of positive squares in only one way, i.e., 321054724 + 161604 = 17918^2 + 402^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 321216296 and 321216305.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20076013 + ... + 20076028.

Almost surely, 2^321216328 is an apocalyptic number.

It is an amenable number.

321216328 is a deficient number, since it is larger than the sum of its proper divisors (281064302).

321216328 is a wasteful number, since it uses less digits than its factorization.

321216328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40152047 (or 40152043 counting only the distinct ones).

The product of its digits is 3456, while the sum is 28.

The square root of 321216328 is about 17922.5089761451. The cubic root of 321216328 is about 684.8559044765.

The spelling of 321216328 in words is "three hundred twenty-one million, two hundred sixteen thousand, three hundred twenty-eight".