205851264128 has 64 divisors (see below), whose sum is σ = 418810419000. Its totient is φ = 100760985600.

The previous prime is 205851264127. The next prime is 205851264167. The reversal of 205851264128 is 821462158502.

It can be written as a sum of positive squares in 4 ways, for example, as 200266990144 + 5584273984 = 447512^2 + 74728^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (205851264127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1061138 + ... + 1240046.

Almost surely, 2^205851264128 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 205851264128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (209405209500).

205851264128 is an abundant number, since it is smaller than the sum of its proper divisors (212959154872).

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

205851264128 is a wasteful number, since it uses less digits than its factorization.

205851264128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179113 (or 179101 counting only the distinct ones).

The product of its (nonzero) digits is 307200, while the sum is 44.

The spelling of 205851264128 in words is "two hundred five billion, eight hundred fifty-one million, two hundred sixty-four thousand, one hundred twenty-eight".