204992640 has 128 divisors (see below), whose sum is σ = 726076800. Its totient is φ = 54660096.

The previous prime is 204992639. The next prime is 204992659. The reversal of 204992640 is 46299402.

204992640 is a `hidden beast` number, since 2 + 0 + 4 + 9 + 9 + 2 + 640 = 666.

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

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 204992595 and 204992604.

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, 11349 + ... + 23211.

It is an arithmetic number, because the mean of its divisors is an integer number (5672475).

Almost surely, 2^204992640 is an apocalyptic number.

204992640 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 204992640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (363038400).

204992640 is an abundant number, since it is smaller than the sum of its proper divisors (521084160).

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

204992640 is a wasteful number, since it uses less digits than its factorization.

204992640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11891 (or 11873 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 204992640 is about 14317.5640386205. The cubic root of 204992640 is about 589.6297974455.

The spelling of 204992640 in words is "two hundred four million, nine hundred ninety-two thousand, six hundred forty".