205511011011 has 12 divisors (see below), whose sum is σ = 296880243088. Its totient is φ = 136993030704.

The previous prime is 205511011001. The next prime is 205511011031. The reversal of 205511011011 is 110110115502.

205511011011 is a `hidden beast` number, since 2 + 0 + 551 + 1 + 0 + 110 + 1 + 1 = 666.

It is not a de Polignac number, because 205511011011 - 2¹⁴ = 205510994627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205511011001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1101175 + ... + 1274208.

Almost surely, 2^205511011011 is an apocalyptic number.

205511011011 is a deficient number, since it is larger than the sum of its proper divisors (91369232077).

205511011011 is a wasteful number, since it uses less digits than its factorization.

205511011011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2385002 (or 2384999 counting only the distinct ones).

The product of its (nonzero) digits is 50, while the sum is 18.

Adding to 205511011011 its reverse (110110115502), we get a palindrome (315621126513).

The spelling of 205511011011 in words is "two hundred five billion, five hundred eleven million, eleven thousand, eleven".