204043561 has 2 divisors, whose sum is σ = 204043562. Its totient is φ = 204043560.

The previous prime is 204043549. The next prime is 204043573. The reversal of 204043561 is 165340402.

It is a balanced prime because it is at equal distance from previous prime (204043549) and next prime (204043573).

It can be written as a sum of positive squares in only one way, i.e., 109098025 + 94945536 = 10445^2 + 9744^2 .

It is a cyclic number.

It is not a de Polignac number, because 204043561 - 2⁵ = 204043529 is a prime.

It is not a weakly prime, because it can be changed into another prime (204041561) 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, 102021780 + 102021781.

It is an arithmetic number, because the mean of its divisors is an integer number (102021781).

Almost surely, 2^204043561 is an apocalyptic number.

It is an amenable number.

204043561 is a deficient number, since it is larger than the sum of its proper divisors (1).

204043561 is an equidigital number, since it uses as much as digits as its factorization.

204043561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 204043561 is about 14284.3817157061. The cubic root of 204043561 is about 588.7184295860.

Adding to 204043561 its reverse (165340402), we get a palindrome (369383963).

The spelling of 204043561 in words is "two hundred four million, forty-three thousand, five hundred sixty-one".