204385691 has 4 divisors (see below), whose sum is σ = 204414432. Its totient is φ = 204356952.

The previous prime is 204385673. The next prime is 204385703. The reversal of 204385691 is 196583402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 204385691 - 2⁶ = 204385627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (204385651) 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, 5006 + ... + 20828.

It is an arithmetic number, because the mean of its divisors is an integer number (51103608).

Almost surely, 2^204385691 is an apocalyptic number.

204385691 is a deficient number, since it is larger than the sum of its proper divisors (28741).

204385691 is a wasteful number, since it uses less digits than its factorization.

204385691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28740.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 204385691 is about 14296.3523669501. The cubic root of 204385691 is about 589.0472903516.

The spelling of 204385691 in words is "two hundred four million, three hundred eighty-five thousand, six hundred ninety-one".