204809155 has 4 divisors (see below), whose sum is σ = 245770992. Its totient is φ = 163847320.

The previous prime is 204809153. The next prime is 204809167. The reversal of 204809155 is 551908402.

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

It is not a de Polignac number, because 204809155 - 2¹ = 204809153 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 204809155.

It is not an unprimeable number, because it can be changed into a prime (204809153) 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, 20480911 + ... + 20480920.

It is an arithmetic number, because the mean of its divisors is an integer number (61442748).

Almost surely, 2^204809155 is an apocalyptic number.

204809155 is a deficient number, since it is larger than the sum of its proper divisors (40961837).

204809155 is an equidigital number, since it uses as much as digits as its factorization.

204809155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40961836.

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 204809155 is about 14311.1549149606. The cubic root of 204809155 is about 589.4538228048.

The spelling of 204809155 in words is "two hundred four million, eight hundred nine thousand, one hundred fifty-five".