316680821 has 2 divisors, whose sum is σ = 316680822. Its totient is φ = 316680820.

The previous prime is 316680757. The next prime is 316680857. The reversal of 316680821 is 128086613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 253159921 + 63520900 = 15911^2 + 7970^2 .

It is an emirp because it is prime and its reverse (128086613) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 316680821 - 2⁶ = 316680757 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (316680121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 158340410 + 158340411.

It is an arithmetic number, because the mean of its divisors is an integer number (158340411).

Almost surely, 2^316680821 is an apocalyptic number.

It is an amenable number.

316680821 is a deficient number, since it is larger than the sum of its proper divisors (1).

316680821 is an equidigital number, since it uses as much as digits as its factorization.

316680821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 316680821 is about 17795.5281180413. The cubic root of 316680821 is about 681.6172729265.

The spelling of 316680821 in words is "three hundred sixteen million, six hundred eighty thousand, eight hundred twenty-one".