205111020 has 48 divisors (see below), whose sum is σ = 582190560. Its totient is φ = 53945856.

The previous prime is 205111019. The next prime is 205111037. The reversal of 205111020 is 20111502.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 205110987 and 205111005.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19035 + ... + 27794.

It is an arithmetic number, because the mean of its divisors is an integer number (12128970).

Almost surely, 2^205111020 is an apocalyptic number.

205111020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205111020 is an abundant number, since it is smaller than the sum of its proper divisors (377079540).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205111020 is a wasteful number, since it uses less digits than its factorization.

205111020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46914 (or 46912 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 205111020 is about 14321.6975250841. The cubic root of 205111020 is about 589.7432762246.

Adding to 205111020 its reverse (20111502), we get a palindrome (225222522).

The spelling of 205111020 in words is "two hundred five million, one hundred eleven thousand, twenty".