321816328 has 8 divisors (see below), whose sum is σ = 603405630. Its totient is φ = 160908160.

The previous prime is 321816323. The next prime is 321816329. The reversal of 321816328 is 823618123.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 272844324 + 48972004 = 16518^2 + 6998^2 .

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 = 321816293 and 321816302.

It is not an unprimeable number, because it can be changed into a prime (321816323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20113513 + ... + 20113528.

Almost surely, 2^321816328 is an apocalyptic number.

It is an amenable number.

321816328 is a deficient number, since it is larger than the sum of its proper divisors (281589302).

321816328 is a wasteful number, since it uses less digits than its factorization.

321816328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40227047 (or 40227043 counting only the distinct ones).

The product of its digits is 13824, while the sum is 34.

The square root of 321816328 is about 17939.2398947113. The cubic root of 321816328 is about 685.2820533815.

The spelling of 321816328 in words is "three hundred twenty-one million, eight hundred sixteen thousand, three hundred twenty-eight".