205511321023 has 8 divisors (see below), whose sum is σ = 216411638400. Its totient is φ = 194619396888.

The previous prime is 205511321017. The next prime is 205511321047. The reversal of 205511321023 is 320123115502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 205511321023 - 2²⁵ = 205477766591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205511321123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2048011 + ... + 2146012.

It is an arithmetic number, because the mean of its divisors is an integer number (27051454800).

Almost surely, 2^205511321023 is an apocalyptic number.

205511321023 is a deficient number, since it is larger than the sum of its proper divisors (10900317377).

205511321023 is a wasteful number, since it uses less digits than its factorization.

205511321023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4196621.

The product of its (nonzero) digits is 1800, while the sum is 25.

Adding to 205511321023 its reverse (320123115502), we get a palindrome (525634436525).

The spelling of 205511321023 in words is "two hundred five billion, five hundred eleven million, three hundred twenty-one thousand, twenty-three".