328916821 has 2 divisors, whose sum is σ = 328916822. Its totient is φ = 328916820.

The previous prime is 328916803. The next prime is 328916831. The reversal of 328916821 is 128619823.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 176517796 + 152399025 = 13286^2 + 12345^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-328916821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (328916831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 164458410 + 164458411.

It is an arithmetic number, because the mean of its divisors is an integer number (164458411).

Almost surely, 2^328916821 is an apocalyptic number.

It is an amenable number.

328916821 is a deficient number, since it is larger than the sum of its proper divisors (1).

328916821 is an equidigital number, since it uses as much as digits as its factorization.

328916821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 40.

The square root of 328916821 is about 18136.0640989163. The cubic root of 328916821 is about 690.2854108772.

The spelling of 328916821 in words is "three hundred twenty-eight million, nine hundred sixteen thousand, eight hundred twenty-one".