204781643 has 24 divisors (see below), whose sum is σ = 243866064. Its totient is φ = 170380800.

The previous prime is 204781631. The next prime is 204781649. The reversal of 204781643 is 346187402.

It is not a de Polignac number, because 204781643 - 2¹⁶ = 204716107 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204781649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 116753 + ... + 118493.

It is an arithmetic number, because the mean of its divisors is an integer number (10161086).

Almost surely, 2^204781643 is an apocalyptic number.

204781643 is a deficient number, since it is larger than the sum of its proper divisors (39084421).

204781643 is a wasteful number, since it uses less digits than its factorization.

204781643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1823 (or 1806 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 35.

The square root of 204781643 is about 14310.1936744406. The cubic root of 204781643 is about 589.4274278588.

The spelling of 204781643 in words is "two hundred four million, seven hundred eighty-one thousand, six hundred forty-three".