205966985856768 has 720 divisors, whose sum is σ = 649278921984000. Its totient is φ = 64761352740864.

The previous prime is 205966985856767. The next prime is 205966985856781. The reversal of 205966985856768 is 867658589669502.

205966985856768 is a `hidden beast` number, since 2 + 0 + 596 + 6 + 9 + 8 + 5 + 8 + 5 + 6 + 7 + 6 + 8 = 666.

It is a super-2 number, since 2×205966985856768² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205966985856767) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 117093225873 + ... + 117093227631.

Almost surely, 2^{205966985856768} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205966985856768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324639460992000).

205966985856768 is an abundant number, since it is smaller than the sum of its proper divisors (443311936127232).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205966985856768 is a wasteful number, since it uses less digits than its factorization.

205966985856768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2922 (or 2899 counting only the distinct ones).

The product of its (nonzero) digits is 94058496000, while the sum is 90.

The spelling of 205966985856768 in words is "two hundred five trillion, nine hundred sixty-six billion, nine hundred eighty-five million, eight hundred fifty-six thousand, seven hundred sixty-eight".