204320591 has 2 divisors, whose sum is σ = 204320592. Its totient is φ = 204320590.

The previous prime is 204320561. The next prime is 204320647. The reversal of 204320591 is 195023402.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 204320591 - 2⁶ = 204320527 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 204320591.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204320551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102160295 + 102160296.

It is an arithmetic number, because the mean of its divisors is an integer number (102160296).

Almost surely, 2^204320591 is an apocalyptic number.

204320591 is a deficient number, since it is larger than the sum of its proper divisors (1).

204320591 is an equidigital number, since it uses as much as digits as its factorization.

204320591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 204320591 is about 14294.0753810801. The cubic root of 204320591 is about 588.9847434898.

Adding to 204320591 its reverse (195023402), we get a palindrome (399343993).

The spelling of 204320591 in words is "two hundred four million, three hundred twenty thousand, five hundred ninety-one".