205388919930 has 256 divisors, whose sum is σ = 539443593216. Its totient is φ = 49929384960.

The previous prime is 205388919859. The next prime is 205388919937. The reversal of 205388919930 is 39919883502.

205388919930 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (205388919937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 187912464 + ... + 187913556.

It is an arithmetic number, because the mean of its divisors is an integer number (2107201536).

Almost surely, 2^205388919930 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205388919930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (269721796608).

205388919930 is an abundant number, since it is smaller than the sum of its proper divisors (334054673286).

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

205388919930 is a wasteful number, since it uses less digits than its factorization.

205388919930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1341.

The product of its (nonzero) digits is 4199040, while the sum is 57.

The spelling of 205388919930 in words is "two hundred five billion, three hundred eighty-eight million, nine hundred nineteen thousand, nine hundred thirty".