205840555830 has 960 divisors, whose sum is σ = 758843914752. Its totient is φ = 39504568320.

The previous prime is 205840555757. The next prime is 205840555831. The reversal of 205840555830 is 38555048502.

205840555830 is a `hidden beast` number, since 2 + 0 + 58 + 40 + 5 + 558 + 3 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205840555831) by changing a digit.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 271915812 + ... + 271916568.

Almost surely, 2^205840555830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205840555830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (379421957376).

205840555830 is an abundant number, since it is smaller than the sum of its proper divisors (553003358922).

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

205840555830 is a wasteful number, since it uses less digits than its factorization.

205840555830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851 (or 835 counting only the distinct ones).

The product of its (nonzero) digits is 960000, while the sum is 45.

The spelling of 205840555830 in words is "two hundred five billion, eight hundred forty million, five hundred fifty-five thousand, eight hundred thirty".