205364423421 has 6 divisors (see below), whose sum is σ = 296637500510. Its totient is φ = 136909615608.

The previous prime is 205364423419. The next prime is 205364423449. The reversal of 205364423421 is 124324463502.

205364423421 is a `hidden beast` number, since 2 + 0 + 5 + 3 + 644 + 2 + 3 + 4 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 168686811225 + 36677612196 = 410715^2 + 191514^2 .

It is not a de Polignac number, because 205364423421 - 2¹ = 205364423419 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 (205364423461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11409134626 + ... + 11409134643.

Almost surely, 2^205364423421 is an apocalyptic number.

It is an amenable number.

205364423421 is a deficient number, since it is larger than the sum of its proper divisors (91273077089).

205364423421 is a wasteful number, since it uses less digits than its factorization.

205364423421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22818269275 (or 22818269272 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 36.

Adding to 205364423421 its reverse (124324463502), we get a palindrome (329688886923).

The spelling of 205364423421 in words is "two hundred five billion, three hundred sixty-four million, four hundred twenty-three thousand, four hundred twenty-one".