204564121 has 2 divisors, whose sum is σ = 204564122. Its totient is φ = 204564120.

The previous prime is 204564109. The next prime is 204564149. The reversal of 204564121 is 121465402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 143161225 + 61402896 = 11965^2 + 7836^2 .

It is a cyclic number.

It is not a de Polignac number, because 204564121 - 2⁹ = 204563609 is a prime.

It is equal to p_11317660 and since 204564121 and 11317660 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (204564161) 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, 102282060 + 102282061.

It is an arithmetic number, because the mean of its divisors is an integer number (102282061).

Almost surely, 2^204564121 is an apocalyptic number.

It is an amenable number.

204564121 is a deficient number, since it is larger than the sum of its proper divisors (1).

204564121 is an equidigital number, since it uses as much as digits as its factorization.

204564121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 204564121 is about 14302.5914085525. The cubic root of 204564121 is about 589.2186544964.

It can be divided in two parts, 2045 and 64121, that added together give a palindrome (66166).

The spelling of 204564121 in words is "two hundred four million, five hundred sixty-four thousand, one hundred twenty-one".