204639400 has 96 divisors (see below), whose sum is σ = 546661440. Its totient is φ = 69788160.

The previous prime is 204639371. The next prime is 204639403. The reversal of 204639400 is 4936402.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (204639403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 437967 + ... + 438433.

It is an arithmetic number, because the mean of its divisors is an integer number (5694390).

Almost surely, 2^204639400 is an apocalyptic number.

204639400 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 204639400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (273330720).

204639400 is an abundant number, since it is smaller than the sum of its proper divisors (342022040).

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

204639400 is a wasteful number, since it uses less digits than its factorization.

204639400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803 (or 794 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 204639400 is about 14305.2228224519. Note that the first 3 decimals coincide. The cubic root of 204639400 is about 589.2909225479.

The spelling of 204639400 in words is "two hundred four million, six hundred thirty-nine thousand, four hundred".