204557 has 2 divisors, whose sum is σ = 204558. Its totient is φ = 204556.

The previous prime is 204521. The next prime is 204563. The reversal of 204557 is 755402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 203401 + 1156 = 451^2 + 34^2 .

It is a cyclic number.

It is not a de Polignac number, because 204557 - 2⁸ = 204301 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102278 + 102279.

It is an arithmetic number, because the mean of its divisors is an integer number (102279).

2²⁰⁴⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

204557 is a deficient number, since it is larger than the sum of its proper divisors (1).

204557 is an equidigital number, since it uses as much as digits as its factorization.

204557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1400, while the sum is 23.

The square root of 204557 is about 452.2797806668. The cubic root of 204557 is about 58.9211817399.

Adding to 204557 its reverse (755402), we get a palindrome (959959).

The spelling of 204557 in words is "two hundred four thousand, five hundred fifty-seven".