205666851964 has 48 divisors (see below), whose sum is σ = 435639366400. Its totient is φ = 82991506176.

The previous prime is 205666851961. The next prime is 205666851997. The reversal of 205666851964 is 469158666502.

It is a junction number, because it is equal to n+sod(n) for n = 205666851899 and 205666851908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205666851961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1099149 + ... + 1272580.

Almost surely, 2^205666851964 is an apocalyptic number.

It is an amenable number.

205666851964 is an abundant number, since it is smaller than the sum of its proper divisors (229972514436).

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

205666851964 is a wasteful number, since it uses less digits than its factorization.

205666851964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2371922 (or 2371920 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 58.

The spelling of 205666851964 in words is "two hundred five billion, six hundred sixty-six million, eight hundred fifty-one thousand, nine hundred sixty-four".