204121305 has 12 divisors (see below), whose sum is σ = 353810340. Its totient is φ = 108864672.

The previous prime is 204121289. The next prime is 204121327. The reversal of 204121305 is 503121402.

It can be written as a sum of positive squares in 2 ways, for example, as 149523984 + 54597321 = 12228^2 + 7389^2 .

It is not a de Polignac number, because 204121305 - 2⁴ = 204121289 is a prime.

It is an unprimeable number.

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 in 11 ways as a sum of consecutive naturals, for example, 2267970 + ... + 2268059.

It is an arithmetic number, because the mean of its divisors is an integer number (29484195).

Almost surely, 2^204121305 is an apocalyptic number.

It is an amenable number.

204121305 is a deficient number, since it is larger than the sum of its proper divisors (149689035).

204121305 is a wasteful number, since it uses less digits than its factorization.

204121305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4536040 (or 4536037 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 204121305 is about 14287.1027503829. The cubic root of 204121305 is about 588.7931906054.

Adding to 204121305 its reverse (503121402), we get a palindrome (707242707).

The spelling of 204121305 in words is "two hundred four million, one hundred twenty-one thousand, three hundred five".