204309840 has 160 divisors (see below), whose sum is σ = 747380736. Its totient is φ = 45181440.

The previous prime is 204309803. The next prime is 204309841. The reversal of 204309840 is 48903402.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 204309798 and 204309807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204309841) 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 31 ways as a sum of consecutive naturals, for example, 50119 + ... + 54041.

Almost surely, 2^204309840 is an apocalyptic number.

204309840 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 204309840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373690368).

204309840 is an abundant number, since it is smaller than the sum of its proper divisors (543070896).

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

204309840 is a wasteful number, since it uses less digits than its factorization.

204309840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3977 (or 3971 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 204309840 is about 14293.6993112350. The cubic root of 204309840 is about 588.9744128521.

The spelling of 204309840 in words is "two hundred four million, three hundred nine thousand, eight hundred forty".