204640 has 24 divisors (see below), whose sum is σ = 483840. Its totient is φ = 81792.

The previous prime is 204623. The next prime is 204641. The reversal of 204640 is 46402.

204640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a d-powerful number, because it can be written as 2¹⁷ + 0 + 6⁵ + 4⁴ + 4⁸ + 0 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 480 + ... + 799.

It is an arithmetic number, because the mean of its divisors is an integer number (20160).

2²⁰⁴⁶⁴⁰ is an apocalyptic number.

204640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

204640 is an abundant number, since it is smaller than the sum of its proper divisors (279200).

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

204640 is a wasteful number, since it uses less digits than its factorization.

204640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1294 (or 1286 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 204640 is about 452.3715287239. The cubic root of 204640 is about 58.9291498478.

The spelling of 204640 in words is "two hundred four thousand, six hundred forty".