321691313 has 2 divisors, whose sum is σ = 321691314. Its totient is φ = 321691312.

The previous prime is 321691303. The next prime is 321691387. The reversal of 321691313 is 313196123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 321556624 + 134689 = 17932^2 + 367^2 .

It is a cyclic number.

It is not a de Polignac number, because 321691313 - 2⁴ = 321691297 is a prime.

It is not a weakly prime, because it can be changed into another prime (321691303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160845656 + 160845657.

It is an arithmetic number, because the mean of its divisors is an integer number (160845657).

Almost surely, 2^321691313 is an apocalyptic number.

It is an amenable number.

321691313 is a deficient number, since it is larger than the sum of its proper divisors (1).

321691313 is an equidigital number, since it uses as much as digits as its factorization.

321691313 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916, while the sum is 29.

The square root of 321691313 is about 17935.7551555545. The cubic root of 321691313 is about 685.1933054175.

The spelling of 321691313 in words is "three hundred twenty-one million, six hundred ninety-one thousand, three hundred thirteen".