321918413 has 2 divisors, whose sum is σ = 321918414. Its totient is φ = 321918412.

The previous prime is 321918407. The next prime is 321918437. The reversal of 321918413 is 314819123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 309654409 + 12264004 = 17597^2 + 3502^2 .

It is an emirp because it is prime and its reverse (314819123) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 321918413 - 2²⁰ = 320869837 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 321918413.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321918013) 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, 160959206 + 160959207.

It is an arithmetic number, because the mean of its divisors is an integer number (160959207).

Almost surely, 2^321918413 is an apocalyptic number.

It is an amenable number.

321918413 is a deficient number, since it is larger than the sum of its proper divisors (1).

321918413 is an equidigital number, since it uses as much as digits as its factorization.

321918413 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 32.

The square root of 321918413 is about 17942.0849680298. The cubic root of 321918413 is about 685.3545063270.

It can be divided in two parts, 32191 and 8413, that added together give a palindrome (40604).

The spelling of 321918413 in words is "three hundred twenty-one million, nine hundred eighteen thousand, four hundred thirteen".