205656645134321 has 8 divisors (see below), whose sum is σ = 211216272044520. Its totient is φ = 200097088708608.

The previous prime is 205656645134309. The next prime is 205656645134329. The reversal of 205656645134321 is 123431546656502.

It can be written as a sum of positive squares in 4 ways, for example, as 84254701889296 + 121401943245025 = 9179036^2 + 11018255^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 205656645134321 - 2¹⁸ = 205656644872177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205656645134329) 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, 11680016 + ... + 23403761.

It is an arithmetic number, because the mean of its divisors is an integer number (26402034005565).

Almost surely, 2^{205656645134321} is an apocalyptic number.

It is an amenable number.

205656645134321 is a deficient number, since it is larger than the sum of its proper divisors (5559626910199).

205656645134321 is a wasteful number, since it uses less digits than its factorization.

205656645134321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35242243.

The product of its (nonzero) digits is 15552000, while the sum is 53.

The spelling of 205656645134321 in words is "two hundred five trillion, six hundred fifty-six billion, six hundred forty-five million, one hundred thirty-four thousand, three hundred twenty-one".