204506 has 4 divisors (see below), whose sum is σ = 306762. Its totient is φ = 102252.

The previous prime is 204487. The next prime is 204509. The reversal of 204506 is 605402.

204506 = 125² + 126² + ... + 136².

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 128881 + 75625 = 359^2 + 275^2 .

It is not an unprimeable number, because it can be changed into a prime (204509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51125 + ... + 51128.

2²⁰⁴⁵⁰⁶ is an apocalyptic number.

204506 is a deficient number, since it is larger than the sum of its proper divisors (102256).

204506 is a wasteful number, since it uses less digits than its factorization.

204506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102255.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 204506 is about 452.2233961219. The cubic root of 204506 is about 58.9162846044.

Adding to 204506 its reverse (605402), we get a palindrome (809908).

The spelling of 204506 in words is "two hundred four thousand, five hundred six".