321918407 has 2 divisors, whose sum is σ = 321918408. Its totient is φ = 321918406.

The previous prime is 321918383. The next prime is 321918413. The reversal of 321918407 is 704819123.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 321918407 - 2⁸ = 321918151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321918437) 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, 160959203 + 160959204.

It is an arithmetic number, because the mean of its divisors is an integer number (160959204).

Almost surely, 2^321918407 is an apocalyptic number.

321918407 is a deficient number, since it is larger than the sum of its proper divisors (1).

321918407 is an equidigital number, since it uses as much as digits as its factorization.

321918407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 321918407 is about 17942.0848008251. The cubic root of 321918407 is about 685.3545020691.

The spelling of 321918407 in words is "three hundred twenty-one million, nine hundred eighteen thousand, four hundred seven".