204564640644 has 192 divisors, whose sum is σ = 653456724480. Its totient is φ = 53892034560.

The previous prime is 204564640571. The next prime is 204564640663. The reversal of 204564640644 is 446046465402.

204564640644 is a `hidden beast` number, since 2 + 0 + 4 + 564 + 6 + 40 + 6 + 44 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 204564640644.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9355164 + ... + 9377004.

It is an arithmetic number, because the mean of its divisors is an integer number (3403420440).

Almost surely, 2^204564640644 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 204564640644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326728362240).

204564640644 is an abundant number, since it is smaller than the sum of its proper divisors (448892083836).

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

204564640644 is a wasteful number, since it uses less digits than its factorization.

204564640644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22827 (or 22819 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 45.

The spelling of 204564640644 in words is "two hundred four billion, five hundred sixty-four million, six hundred forty thousand, six hundred forty-four".