204916864640 has 128 divisors (see below), whose sum is σ = 517444139520. Its totient is φ = 77477621760.

The previous prime is 204916864589. The next prime is 204916864651. The reversal of 204916864640 is 46468619402.

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 733022 + ... + 973218.

It is an arithmetic number, because the mean of its divisors is an integer number (4042532340).

Almost surely, 2^204916864640 is an apocalyptic number.

204916864640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 204916864640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (258722069760).

204916864640 is an abundant number, since it is smaller than the sum of its proper divisors (312527274880).

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

204916864640 is a wasteful number, since it uses less digits than its factorization.

204916864640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240290 (or 240278 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 50.

The spelling of 204916864640 in words is "two hundred four billion, nine hundred sixteen million, eight hundred sixty-four thousand, six hundred forty".