205021055 has 4 divisors (see below), whose sum is σ = 246025272. Its totient is φ = 164016840.

The previous prime is 205021021. The next prime is 205021081. The reversal of 205021055 is 550120502.

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

It is not a de Polignac number, because 205021055 - 2²⁰ = 203972479 is a prime.

It is a super-3 number, since 3×205021055³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20502101 + ... + 20502110.

It is an arithmetic number, because the mean of its divisors is an integer number (61506318).

Almost surely, 2^205021055 is an apocalyptic number.

205021055 is a deficient number, since it is larger than the sum of its proper divisors (41004217).

205021055 is an equidigital number, since it uses as much as digits as its factorization.

205021055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41004216.

The product of its (nonzero) digits is 500, while the sum is 20.

The square root of 205021055 is about 14318.5563168917. The cubic root of 205021055 is about 589.6570399791.

Adding to 205021055 its reverse (550120502), we get a palindrome (755141557).

The spelling of 205021055 in words is "two hundred five million, twenty-one thousand, fifty-five".