321660613 has 2 divisors, whose sum is σ = 321660614. Its totient is φ = 321660612.

The previous prime is 321660569. The next prime is 321660623. The reversal of 321660613 is 316066123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171034084 + 150626529 = 13078^2 + 12273^2 .

It is a cyclic number.

It is not a de Polignac number, because 321660613 - 2¹⁷ = 321529541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321660623) 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, 160830306 + 160830307.

It is an arithmetic number, because the mean of its divisors is an integer number (160830307).

Almost surely, 2^321660613 is an apocalyptic number.

It is an amenable number.

321660613 is a deficient number, since it is larger than the sum of its proper divisors (1).

321660613 is an equidigital number, since it uses as much as digits as its factorization.

321660613 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 321660613 is about 17934.8993027561. The cubic root of 321660613 is about 685.1715080165.

The spelling of 321660613 in words is "three hundred twenty-one million, six hundred sixty thousand, six hundred thirteen".