205564946409 has 6 divisors (see below), whose sum is σ = 296927144826. Its totient is φ = 137043297600.

The previous prime is 205564946387. The next prime is 205564946459. The reversal of 205564946409 is 904649465502.

205564946409 is a `hidden beast` number, since 2 + 0 + 556 + 4 + 9 + 46 + 40 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 189548778384 + 16016168025 = 435372^2 + 126555^2 .

It is not a de Polignac number, because 205564946409 - 2²⁷ = 205430728681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205564946459) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11420274792 + ... + 11420274809.

It is an arithmetic number, because the mean of its divisors is an integer number (49487857471).

Almost surely, 2^205564946409 is an apocalyptic number.

It is an amenable number.

205564946409 is a deficient number, since it is larger than the sum of its proper divisors (91362198417).

205564946409 is a wasteful number, since it uses less digits than its factorization.

205564946409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22840549607 (or 22840549604 counting only the distinct ones).

The product of its (nonzero) digits is 9331200, while the sum is 54.

The spelling of 205564946409 in words is "two hundred five billion, five hundred sixty-four million, nine hundred forty-six thousand, four hundred nine".