205672921856 has 144 divisors (see below), whose sum is σ = 458284095360. Its totient is φ = 91550269440.

The previous prime is 205672921789. The next prime is 205672921879. The reversal of 205672921856 is 658129276502.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 205672921798 and 205672921807.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67058435 + ... + 67061501.

It is an arithmetic number, because the mean of its divisors is an integer number (3182528440).

Almost surely, 2^205672921856 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 205672921856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (229142047680).

205672921856 is an abundant number, since it is smaller than the sum of its proper divisors (252611173504).

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

205672921856 is a wasteful number, since it uses less digits than its factorization.

205672921856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3930 (or 3916 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 53.

The spelling of 205672921856 in words is "two hundred five billion, six hundred seventy-two million, nine hundred twenty-one thousand, eight hundred fifty-six".