204723640 has 32 divisors (see below), whose sum is σ = 502504560. Its totient is φ = 74444800.

The previous prime is 204723637. The next prime is 204723647. The reversal of 204723640 is 46327402.

It is a junction number, because it is equal to n+sod(n) for n = 204723599 and 204723608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204723647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 232201 + ... + 233080.

Almost surely, 2^204723640 is an apocalyptic number.

204723640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

204723640 is an abundant number, since it is smaller than the sum of its proper divisors (297780920).

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

204723640 is a wasteful number, since it uses less digits than its factorization.

204723640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465303 (or 465299 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 28.

The square root of 204723640 is about 14308.1668986632. The cubic root of 204723640 is about 589.3717721744.

It can be divided in two parts, 2047236 and 40, that added together give a triangular number (2047276 = T₂₀₂₃).

The spelling of 204723640 in words is "two hundred four million, seven hundred twenty-three thousand, six hundred forty".