204849821 has 4 divisors (see below), whose sum is σ = 223472544. Its totient is φ = 186227100.

The previous prime is 204849803. The next prime is 204849851. The reversal of 204849821 is 128948402.

204849821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 204849821 - 2²⁶ = 137740957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204849851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9311345 + ... + 9311366.

It is an arithmetic number, because the mean of its divisors is an integer number (55868136).

Almost surely, 2^204849821 is an apocalyptic number.

It is an amenable number.

204849821 is a deficient number, since it is larger than the sum of its proper divisors (18622723).

204849821 is a wasteful number, since it uses less digits than its factorization.

204849821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18622722.

The product of its (nonzero) digits is 36864, while the sum is 38.

The square root of 204849821 is about 14312.5756242544. The cubic root of 204849821 is about 589.4928333377.

The spelling of 204849821 in words is "two hundred four million, eight hundred forty-nine thousand, eight hundred twenty-one".