204681557 has 4 divisors (see below), whose sum is σ = 206037216. Its totient is φ = 203325900.

The previous prime is 204681517. The next prime is 204681559. The reversal of 204681557 is 755186402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 204681557 - 2⁶ = 204681493 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 204681557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204681559) 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 in 3 ways as a sum of consecutive naturals, for example, 677603 + ... + 677904.

It is an arithmetic number, because the mean of its divisors is an integer number (51509304).

Almost surely, 2^204681557 is an apocalyptic number.

It is an amenable number.

204681557 is a deficient number, since it is larger than the sum of its proper divisors (1355659).

204681557 is a wasteful number, since it uses less digits than its factorization.

204681557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1355658.

The product of its (nonzero) digits is 67200, while the sum is 38.

The square root of 204681557 is about 14306.6962293885. The cubic root of 204681557 is about 589.3313856449.

The spelling of 204681557 in words is "two hundred four million, six hundred eighty-one thousand, five hundred fifty-seven".