204021155 has 32 divisors (see below), whose sum is σ = 276756480. Its totient is φ = 143256960.

The previous prime is 204021151. The next prime is 204021163. The reversal of 204021155 is 551120402.

It is not a de Polignac number, because 204021155 - 2² = 204021151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (204021151) 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 31 ways as a sum of consecutive naturals, for example, 357020 + ... + 357590.

It is an arithmetic number, because the mean of its divisors is an integer number (8648640).

Almost surely, 2^204021155 is an apocalyptic number.

204021155 is a deficient number, since it is larger than the sum of its proper divisors (72735325).

204021155 is a wasteful number, since it uses less digits than its factorization.

204021155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 851.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 204021155 is about 14283.5974110166. The cubic root of 204021155 is about 588.6968797628.

Adding to 204021155 its reverse (551120402), we get a palindrome (755141557).

The spelling of 204021155 in words is "two hundred four million, twenty-one thousand, one hundred fifty-five".